In Sheep, an Upside To Immune Weakness

A weak immune system makes an animal vulnerable to disease and parasites, but strangely, natural (0) …. does not always weed out (1) … that have what appear to be severe disadvantages, according to a new study. That may be because the (2) … confer some advantages. The study it is also associated with (3) …reproductive success. The last (4) … of St. Kilda moved away about 80 years ago because of the harsh winters and difficult living conditions. But they left behind their sheep, unmanaged and (5) … freely. No longer selected by (6) … , the sheep are now subject to natural selection. Scientists sampled sheep feces to count parasites and drew blood from the sheep to measure antibody (7) … .They found that the average life span of the 410 ewes surveyed was 6 years. But there was a wide (8) …, with some living 15 years, and many others dying at age 3 or 4. The short-lived ewes had lower concentrations of antibodies than the longer-lived ones, which suggested why their lives were so short. But why was natural selection not (9) … them out? The answer, she said, was that the short-lived ewes were more (10) … to produce lambs. Those that died young reproduced almost every year, often having twins. Sheep that lived longer did not reproduce every year.

0 - SELECT, 1 - CREATE 2 - WEAK 3 - REDUCE, 4 - HABIT 5 – ROAM, 6 - BREED 7 -PRODUCT 8 - VARY 9 - WEED 10 - LIKE

Exercise 6.For questions 1-10,read the text below. Use the word given in capitals at the end of each line to form a word that fits in the space in the same line. There is an example at the beginning (0).

Example 0 essential

ARTHRITIS

Arthritis is a general term for aches and pains in the body's joints. Most types of arthritis involve the deterioration of cartilage, which is an (0) ….material covering the ends of the bones in the joint. When the (1) …. Cartilage wears out, it becomes rough and this causes pain when the joint moves. This condition is more common among the elderly, but some people can be (2) … from (3) ..… . Apart from (4) … painkillers, little or no treatment is available. However, (5) …scientists have designed(6) …joints that can replace the (7) … , worn-out ones. These new joints could prove very (8)… to arthritis sufferers. Although some believe that joint replacement may be (9) …, numerous patients are (10) … waiting for this medical breakthrough.

0- ESSENCE 1 - HEALTH 2 - SUFFER, 3 – CHILD, 4 - TRADITION 5 - AMBITION 6 – ARTIFICE, 7 - PAIN, 8 - BENEFIT 9 – COST, 10 -ANXIOUS

Exercise 7.For questions 1-10,read the text below. Use the word given in capitals at the end of each line to form a word that fits in the space in the same line. There is an example at the beginning (0).

Example 0 officially

The longest-living person (0) … recorded lived to be 122 years old and 164 days old. In general, the number of people who live to be over one hundred is increasing, especially among women, yet there isn't a single (1) …who can fully explain this phenomenon. Some of them claim that it's purely a (2) …fact. However, in the developing countries, where (3) … progress is slower, life expectancy is much less. According to (4) …records, life expectancy for these people is about forty years. (5) … reasons are mainly responsible for this and as a result a high (6) … of the population suffers from malnutrition. One must also (7)… the fact that sanitary conditions in developing countries are rather (8) … . To (9) … , proper housing and sanitation, adequate healthcare and a(n) (10) … diet play an important role in a person's life expectancy.

0 - OFFICIAL 1 - SCIENCE 2 - BIOLOGY 3 - SCIENCE 4 - MEDICINE 5 – ECONOMICS 6 - PER CENT 7 - EMPHASIS 8 - HYGENE, 9 - SUMMARY 10 - NUTRITION

Exercise 8.For questions 1-8, complete the second sentence so that it has a similar meaning to the first sentence, using the word given. Do not change the word given. You must use between two and five words, including the word given. Here is an example (0).

Example:

(0)There won't be any oil left soon.

RUN

We will.. run out of... oil soon.

1 I'm still optimistic about climate change although the predictions are depressing.

DESPITE

I'm still optimistic about climate change predictions … .

2 Endangered species will become extinct if we don't do more to protect them.

UNLESS

Endangered species will become extinct................... to protect them.

3 Rising sea levels are a real threat to many coastal regions.

RISK

Many coastal regions...................... rising sea levels.

4 Governments have done too little to protect the environment.

ENOUGH

Governments...................... to protect the environment.

5 I always travel to work by train so that I don't waste time in traffic jams.

AVOID

I always travel to work by train.................... traffic jams.

6 It hasn't rained for six months.
SINCE

It....................... it rained.

7 The lake always used to freeze over in the winter.
WOULD

The lake....................... in the winter.

8 He left before the thunderstorm started.
ALREADY

He....................... the thunderstorm started.

Exercise 9.For questions 1-8, complete the second sentence so that it has a similar meaning to the first sentence, using the word given. Do not change the word given. You must use between two and five words, including the word given. Here is an example (0).

Example:

0Children's diets are not as healthy as they used to be.
MORE

Children's diets are ...more unhealthy than … they used to be.

1 The doctor said I should give up smoking.
ADVISED

The doctor....................................................... smoking.

2 You won't lose weight unless you stop eating junk food.
IF

You won't lose weight............................................ eating junk food.

3 Parents who have overweight children, should be given special help.

WHOSE

Parents........................................................ should be given special help.

4 'Why don't we go for a jog?' Mike said.
SUGGESTED

Mike........................................................ for a jog.

5 I expect people ate more vegetables in the past.
MUST

People........................................................ in the past.

6 I didn't start playing tennis until I was fifteen.
WHEN

I started........................................................ fifteen.

7 Til give you a check-up next week,' said Amy's doctor.

TOLD

The doctor....................................................... give her a check-up the following week.

8 Ella was so tired she couldn't study properly.
TOO

Ella........................................................ study properly.

Exercise 10.For questions 1-8, complete the second sentence so that it has a similar meaning to the first sentence, using the word given. Do not change the word given. You must use between two and five words, including the word given. Here is an example (0).

0 The washing machine is not working properly.
WRONGThere is something wrong with the washing machine.

1 Unfortunately, most people didn't have a good time at the party.
HARDLY

Unfortunately,____ .

2 I didn't like a single song from their new CD.
NONE

I from their new CD.

3I'm pretty sure that Mary doesn't like jazz music and Susan doesn't either.
DISLIKE

I'm pretty sure that_______ .

4 There isn't enough petrol on the market.
LACK

There is________________________ .

5 We realised that both cars were expensive.
CAR

We realised that___________________ .

6 There aren't a lot of things to remember from that awful trip.
LITTLE

There________ from that awful trip.

7 I'm afraid I can't study both Maths and Physics tonight - just one of the two.
OR

I'm afraid I can___________ .

8 They were looking for their lost dog all week.
THE

They spent_________________________ looking for the lost dog.

9 The concert was sold out two weeks in advance.
ANY

There________________________________ for the concert two weeks in advance.

Exercise 11.For questions 1-12, read the text below and think of the word which best fits each gap. Use only one word in each gap. There is an example at the beginning (0).