3/You can't leave the hall .... the test.

4/We ..... a wonderful dinner yesterday evening

5/Oxygen and hydrogen ........ water

6/I'm going to see him ..... four o'clock this afternoon

7/look! They .. the house

8/Brush your .... after every meal

9/When the man was injured , an ambulance ..... to the hospital

10/I might fail the entrance exam if .... improve.

11/I tried my best but ! ...... do the exercise

12/He ..... a car when he was 16

13/I felt a sleep .... I was watching Tv

14/I'm ... some shopping for my holiday

15/I can't stand ... in hot weather

16/Would you mind .... the window ?

17/Youssef. .... a cold, so he stayed home

18/If the weather is humid , the air is. .....

19/Many situations in life. .... some knowledge of mathemayics

20/Pleas , ....... be angry , I'm only joking.