Unit 3 The human body, 3F Reading, Body clock, page 35
Exercise 1
1 а record
b record
2 a exercise
b exercise
3 a work
b work
4 a show
b show
5 a rest
b rest
6 a hard
b hard
7 a light
b light
8 a level
b level
Exercise 2
Yes
Exercise 3
1 C
2 A
3 B
4 C