Choose the best answer to complete the following

CONDITIONAL SENTENCES
Choose the best answer to complete the following. sentences.
1.If it...........convenient, let's go out for a drink tonight.
a.be. b.was.
c.were. d.is.
2.If you..........time,please write to me.
a.have. b.have had.
c.had. d.has.
3.If you had had the chance,..............you go finishing?
a.did. b.would.
c.may. d.do.
4.Trees won't grow................there is enough water.
a.if. b.when.
c.unless. d.as.
5.If you ................. to my advice in the first place,you wouldn't be in this mess right now.
a.listen. b.had listened.
c.will. d.listened.
6.I wish I............you some money for your rent,but I'm broke myself.
a.can lend. b.could lend.
c.would lend. d.will lend.
7.If someone..............into the store,smile and say,"May I help you?"
a.comes. b.came.
c.would come. d.could lend.
8.If you stay up late the previous night,you.............sleepy the next morning.
a.feel. b.to feel.
c.feels. d.will feel.
9.If Peter.........,he will be sad because she wants to meet him very much
a.comes. b.do not come.
c.does not come. d.will come.
10.If his teeth still........m...,he will have to go to the dentist's again.
a.hurt. b.hurts.
c.to hurt. d.will hurt.