Відповідь:
5. B) faster
1. C) -, a
2. B) They, their
6. Непонятно из чего делать предложения О_о и что означают цифры снизу тоже, а так:
It must be hard to study math.
We have been on an excursion the whole day.
Not going to lie, studying at night is almost impossible.
Doing sports can be very enjoyable.
It's not always easy to communicate with your classmates.