Supply the correct verb form to complete the following sentences

supply the correct verb form to complete the following sentences :1 if the weather (clear)...................... we'll go for a walk
2.If it is fine tomorrow , we (go) .........for a pinic
3.If I (have) ..... time tonight , I ' ll finish the novel I'm reading
4.If it (rain) ..... next weekend , we ươn't be able to plant vegetables
5.If he is leaving at 6 o'clock , I (ask) ... him to give me a lift 
6.If she has drivenall that way since this morning , she ( be) ..... tired and hungry 
7. We shouldn't throw rubbish carelessly if we ( not want) .....our environment polluted 
8.Lan can't pass the coming exam if she ( not study) .....hard for it