下列有关酶的叙述，正确的是（） A.高温和低温均能破坏酶的结构使其失去活性 B.酶是

单句改错

1. I don't like football and basketball. 

2. He does his homework very careful.  

3. Running is much easy than cycling. 

4. The weather is very well. Let's go out to play.

5. Table tennis is popularer than skiing in China. 

She asked me to help her,  ________that she couldn't move the heavy suitcase.[      ]

A. only to realize  

B. having realized

C. having been realized  

D. realized

门诊治疗时放射性活度应小于（）。

A.5mCi

B.10mCi

C.20mCi

D.25mCi

E.30mCi

The discourse theory was established by ______ in the late 1970s and developed from M. A. K. Halliday's theory of first language acquisition.

A. E. Hatch



B. M.A.K. Halliday
C. Stephen Krashen


D. Joseph H. Greenberg

关于右肺的描述，下列哪项是正确的

A．比左肺窄而长

B．通过一斜裂分为上、下两叶

C．前缘锐利有心切迹

D．位于右胸膜腔内

E．右肺可分为10个肺段