А, Проанализируйте предложения и определите, какое суще- ствительное заменяется союзом which/thаt или who (выполия
ющим функцию подлежащего в придаточном предложении):
глагол-сказуемое, стоящий после союза, имеет или не имеет
окончание «s» в зависимости от числа существительного, кото-
рое заменяется этим союзом.
Например:
The human body consists of cells which vary in size and
shape.
Our body is a machine that works day and night.
1. The skin, our largest organ, is a flexible protective shield that
maintains body moisture.
2. An organ system consists of two or more organs which perform
a specific task.
3. People who exercise regularly feel healthy.
4. People who exercise feel stronger than those who do not.
5. People who are physically active are less susceptible to the type
2 of diabetes.
6. Healthy joints contain an important fluid that lubricates and
nourishes them.
7. The human body has millions of cells that require nutrients and
energy.

Объяснение:

My favourite animal is a cat. It can be white, black, gray, brown and other colour. I like the gray cats with striped fur.

This animal has got four legs and a tail. It is about one half a metre long and it weighs a few kilograms.

When cats are little kittens, they are very playful and funny. Each cat has its own character, but all of them are very careful and clever.

перевод

Моё любимое животное — кошка. Она может быть белого, чёрного, серого, коричневого и другого цвета. Мне нравятся серые кошки с полосатым мехом.

Это животное имеет четыре ноги и хвост. Оно около полутора метров в длину и весит несколько килограммов.

Когда кошки маленькие котята, они очень игривы и забавны. Каждая кошка имеет свой собственный характер, но все они очень осторожны и умны.

However, my favourite animal is dog. I simply adore dogs of various breeds. Mine is a French Bulldog of a black colour with rare white spots. It’s not tall but is fat. It has a funny face with big ears and almost no tail. Bobby is a wonderful dog and a faithful friend. I think it also likes us, because it often shows deep affection. When necessary, Bobby can become rather protective and scare the enemies away. The distinctive feature of this breed is its stubborn nature, so it’s not easy to train such dogs. They require lots of patience and repetition.

In my opinion, the dogs’ role in human society is invaluable. Apart from being a good friend, they have always performed the role of a hunter, a herder, a protector, a military or police companion and most importantly a guide for the handicapped people. Some dogs are so intelligent that they are trained to look for criminals or victims of natural disasters. They can easily sniff out explosives or drugs, so the police often consider them to be the best helpers. I was surprised to know that when a police dog dies, it receives a full funeral. Sometimes, when dealing with unpleasant and traitorous people, I think that they should learn a lot from dogs.