以下反应属于RNA编辑的是
A．转最后碱基的甲基化
B．转录后产物的剪接
C．转录后产物的剪切
D．转录产物中核苷酸残基的插入、删除和取代
参考答案：D
F级绝缘材料的耐热程度是（）度。
A、130
B、155
C、180
D、95
用所给单词的适当形式填空。
1. My mother is used to (go) shopping on Sundays.
2. They go out of their way to make me ____ (feel) at home.
3.I find it difficult (understand) everything.
4. His bike is (difference) from mine.
5. There is no reason___ (come) to school late today.
