下列做法属于减小摩擦的是（  ）

下列各句中，没有语病的一项是（    ）

阅读理解What are the children doing?
    What are you doing, children? Oh, we are playing games. Look at Li Lei. He is throwing the frisby with Jim. What about the twins? They are flying kites. The kites are very nice. One like a bird, the other is like a plane. Li Tao is playing basketball with me. Han Mei and Ma Lin are singing an English song under a big tree.

下列各句中没有语病的一项是（   ）

In this institution, a medal, together with a prize of a certain sum of money, ________ does best in science and technology every two years.