Making questions

Make questions for these answers
1) Last month.
2) Because he had to study Maths.
3) While she was doing her homework.
4) I'll have a cheese sandwich.
5) There were 25 people.
6) No, you don't have to.
7) When she was a little girl.
8) A few.
9) For over 20 years.
10) Tom lives 10 blocks from here.
11) The Eiffel Tower was built many years ago.
12) This book was written by Michael Vince.
13) No, thank you.
14) People grow tea in China.
15) They're going to visit their uncle next weekend.
16) Once a week.
17) Since 2001
18) He's 1.70m tall.
19) I haven't seen her for ages.
20) It's made of plastic.