【单选题】下列有关实验操作 “先”与“后”的说法中正确的是
A.
实验室制取气体,先把药品装入试管,再检查装置气密性
B.
加热氯酸钾制 O 2 并用排水法收集,实验完毕先熄灭酒精灯后从水槽中移出导管
C.
一氧化碳还原化铜,先加热氧化铜粉末至红热,后通入一氧化碳气体
【单选题】Darwin’s thinking both drew upon and __________ the conventional ideas of his time.
【单选题】Darwin's thinking both drew upon and _________ the conventional ideas of his time.
【单选题】Darwin’s thinking both drew upon and _______ the conventional ideas of his time.
【单选题】党的十三大根据邓小平的论述,提出了( )是当今世界的两大主题。
【单选题】Darwin's thinking both drew upon and _______ the conventional ideas of his time.
【单选题】党的十三大根据邓小平的论述提出,当今世界的两大主题是:( )
【单选题】Darwin's thinking both drew upon and _________ the conventional ideas of his time.