多项选择题

In this paragraph, __________.

A．the protagonist was Neil Armstrong
B．there were two minor characters
C．a description of the moon was given
D．the writer did not include a theme

你可能感兴趣的试题

单项选择题

淀粉和葡萄糖的分离多采用？（）

A．氧化铝层析
B．离子交换层析
C．聚酰胺层析
D．凝胶层析

单项选择题

首先确定研究题目，然后开始查找文献。
A、正确
B、错误