1 help/ will do
2. will water/ stays
3 has/will buy
4 often/ will take
5. will have / live
6. has he done / has done
7 begun
8 does not
9 has
10 studys
b2
1 Without water, trees and fish will die
2 When you are free, you cannot help your parents
3 If you have money, he'll lend you some