Нужна помощь по английскому

Там всё вроде верно, либо я ошибочно сообразила, что нужно делать?

7 Correct mistakes.

1 I am not busy at the weekends.

2 The student is not responsible for his work at the university.

3 Do medical students study anatomy?

4 In Ukraine there is a wide network of higher medical institutions.

5 The scientists are still doing research in the field of medicine.

6 The equipment of the laboratory is modern and it presents great

facilities for learning chemistry.

7 My everyday activities are quite routine but they still require a lot of

time.

8 The sciences we study are difficult but good knowledge of them is necessary for my future profession.