15. Please don’t disturb him if he (be).............................................. busy. 16. If ice (be).................................. heavier than water, it (not float)........................................... 17. They would be glad if the rain (stop)………………………soon. 18. If Jack (come) ………………………….to my party, I would have danced with him. 19. It’s too bad Helen isn’t here. If she (be) ……………..here, she (know) …………………….. what to do. 20. Lee will go to a Disneyland if he (save) ………………………… enough money

15. is

16. is/will not float

17. stopped

18. had come

19. were/would know

20. saves

15. Please don’t disturb him if he (be)...........is................................... busy.

16. If ice (be)..........is........................ heavier than water, it (not float).......won't float....................................

17. They would be glad if the rain (stop)……stopped…………………soon.

18. If Jack (come) ……had come…………………….to my party, I would have danced with him.

19. It’s too bad Helen isn’t here. If she (be) ……were………..here, she (know) …would know………………….. what to do.

20. Lee will go to a Disneyland if he (save) ……saves…………………… enough money