1)

 Where were you ___ 28 February?

A)

 on

B)

 in

2)

 She wrote a lot of letters ___ she was on holiday.

A)

 during

B)

 while

3)

 When do you arrive ___ work in the morning?

A)

 in

B)

 at

4)

 Water wasn’t clean ___ we didn’t go swimming.

A)

 so

B)

 because

5)

 Do you mind ___ I close the window?

A)

 if

B)

 when

6)

 I don’t like people ___ never stop talking.

A)

 who

B)

 which

7)

 She likes looking at stars in the sky ___ night.

A)

 at

B)

 in

8)

 He stayed with us ___ several days.

A)

 since

B)

 for

9)

 The dog swam ___ the river.

A)

 over

B)

 across

10)

 She often goes to work ___ foot.

A)

 on

B)

 by