____time,Chinese farmers have invented many farming techniques.

I don’t think Tom’s remarks on his monitor are ______；he is not supposed to say so.

When you are on the bus to work in the morning, smile to the people sitting beside you, you will get his smile ______.

Because natural disasters occur at random times, it is difficult to warn people _______.

My brother gave me a present for my birthday but I gave him nothing ______ his.

An increasing number of products made in China are      good quality but much less    expensive than those from abroad.

Mother said she was by no means annoyed; ________, she was happy to be able to make her guests feel at home.

          passion, people won't have the motivation or the joy necessary for creative thinking.

Researches are convinced ______ the positive effect of laughter ______ physical and mental health.

     sales of cars up by 30% last year, the traffic in Beijing has become increasingly terrible.