If people ______(drive) more slowly, there wouldn’t be so many accidents. 2.If you had worked carefully, you _____(not make) so many mistakes. 3.The boat wouldn’t have drifted away, if we _____ (tie) it up. 4.If I had known you already _____(have) a typewriter, I _____(not, buy) one for your birthday. 5.If he _____(be) here this afternoon I would go with him. 6.If it were to rain tomorrow, the match _____(postpone). 7.But for your help, we ______(not be) able to finish the work in time. 8.If it _____(not, be) for the leadership of the Party, we would not have achieved so much. 9.I wish I _____(study) hard while I was young. 10.It is about time that fence ______(mend). 11.My request is that we ______(hold) another session to discuss the problem. 12.It is strange that the car _____(break) down at exactly the same place where it _____(break) down yesterday. 13.The baby smiled as if he _____(understand) what his mother _____(say). 14.He talked as if he _____(do) all the work himself, but in fact Tom and I _____(do) most of it. 15.If only we _____(have) a phone! I’m tired of queuing outside the public phone box.