Science and technology have in important ways __________ the improvement of agricultural production.

My mobile phone disappeared. Where _____ I have left it?

Liu Guozheng, together with Kong Linhui, _____China in men’s table tennis singles event in the Sydney Olympic Games. [ ]

October 15 th is my birthday, ________ I will never forget.

There ______________ in spring in Suzhou, but the weather there is usually nice at this time of year.