普通光学显微镜的分辨极限是（）。
A.0.2纳米
B.0.2微米
C.0.2厘米
D.0.2毫米
参考答案：B
1mol某有机物A能与1mol氢气发生加成反应，产物是2,2,3－三甲基戊烷，A可能是__________，_________ ，__________ 。
A. To ask the man to read the book together. B. To request the man to write a term paper for her. C. To complain about the number of reading materials. D. To ask for some advice on how to select the reading materials.
