сделать : 1. If there (be) any snow round there, we (go) skiing. 2.If my friend (know) my address, he (find) my house. 3.If I (receive) your letter, I (answer) it. 4.If he (give up) smoking, he (look) better. 5.If we ( invite) them, they (come) to our party. 6.If I (know) they need me, I (come) at once. 7.If we (learn) the truth, she (be) very angry. 8.If he (study) more, he (pass) his exam easily. 9.If the story hadn’t been true, the newspaper (not print) it. 10.We (go) by air if we (have) enough money

1. If there had been any snow round there,we would have gone skiing.  

2.If my friend had known my address, he would have found my house.  

3.If I had received your letter, I would have answered it.  

4.If he had given up smoking, he would have looked better.  

5.If we had invited them, they would have come to our party.  

6.If I had known they needed me, I would have come at once.  

7.If we had learnt the truth, she would have been very angry.  

8.If he had studied more, he would have passed his exam easily.  

9.If the story hadn’t been true, the newspaper wouldn't have printed it.  

10.We would have gone by air if we had had enough money.

Объяснение: