两个大小分别为5N和8N的共点力，它们合力的大小可能是（ ） A．1N B．2N

一年中______是大月，______是小月．

At yesterday’s meeting, some are against his plan while others are ______ it, with no agreement reached.

A．in favour of

B．in place of

C．in search of

D．in honour of

You must trust him;he is a man who___  his promise.  [ ]

A. speaks out    

B. lives up to  

C. depends on    

D. keeps on

诗句“三峰一一青如削，卓立千寻不可干”描写的是（）的景色。

A.仙都山

B.江郎山

C.飞来峰

D.雁荡山

化学致癌的各阶段有何特征？