chia động từ :
1.we can save natural resources if we (use) solar energy
2.he'd have a lot of friends if he (not be) so selfish
3.if it doesn't rain soon,the crop (lose)
4.if these (not be) electricity,people (can't) use house hold appdiances
5.unless he (study) hard ,he will pass the final exam
6.if the sun(stop) shining ,what (happen) to our planet?
7.what you (wish)if a fairy (give) you three wishes?
8.if i (know) his telephone number,i'd give it to you
9.if i had a type writes i (type)it myself
10.he might get fat if he (stop)smoking