Ⅰ Complete the sentences with right forms of the words.
1. If the weather ______ (be) fine, we ______ (go) for a picnic.
2. What ______ he ______ (do) if he ______ (have) time?
3. If you ______ (want) to come to my home, please ______ (let) me know first.
4. If Kelly ______ (not have) a child, she ______ (keep) a pet dog.
5. Linda ______ (buy) a new computer if the old one ______ (not work).
6. The twins ______ (fight) with each other if they ______ (argue) (吵架).
7. If winter ______ (come), ______ spring ______ (be) far behind?
8. If you ______ (not have) a good rest, you ______ (feel) tired.
9. I ______ (go) to the beach if it ______ (not rain) this week.
10. ______ they ______ (have) a match if the PE teacher ______ (be) busy?

【解析】：本题考查if引导的条件状语从句，遵循“主将从现”原则，即主句用一般将来时，从句用一般现在时；当主句为祈使句或含有情态动词时，从句仍用一般现在时。
1. 从句主语weather是不可数名词，be动词用is；主句用一般将来时will go。
2. 主句是特殊疑问句，将will提前，动词用原形do；从句主语he是第三人称单数，have用has。
3. 主句是祈使句，用动词原形let；从句主语you是第二人称，want用原形。
4. 从句主语Kelly是第三人称单数，否定形式用doesn't have；主句用will keep。
5. 从句主语the old one是第三人称单数，否定形式用doesn't work；主句用will buy。
6. 从句主语they是复数，动词用原形argue；主句用will fight。
7. 从句主语winter是不可数名词，动词用comes；主句是一般疑问句，将will提前，动词用be。
8. 从句主语you是第二人称，否定形式用don't have；主句用will feel。
9. 从句主语it是第三人称单数，否定形式用doesn't rain；主句用will go。
10. 主句是一般疑问句，将will提前，动词用have；从句主语the PE teacher是第三人称单数，be动词用is。
【答案】：1. is, will go 2. will, do, has 3. want, let 4. doesn't have, will keep 5. will buy, doesn't work 6. will fight, argue 7. comes, will, be 8. don't have, will feel 9. will go, doesn't rain 10. Will, have, is