It's bad for a man to smoke in the public places where smoking is not allowed.
In the experiment the scientist kept a watchful eye________the developments and recorded every detail.
He has some trouble ______ his classmates, but he has no trouble ______ doing his lessons.
I bargained with the shopkeeper for a long time, and finally we agreed________the price.
________the rapid growth of short messages which are sent by mobile phones, the number of criminal cases through short messages are increasing.
— Have you read the book War and Peace________Tolstoy?— No. I’ve never heard of it.