问题 选择题

下列错误的实验操作中,可能引发安全事故的是(  )

A.

取用液体

B.

点燃酒精灯

C.

取用固体

D.

过滤

答案

A、取用液体时:①试剂瓶瓶口要紧挨试管口,防止液体流出;②标签向着手心,防止液体流出腐蚀标签;③瓶塞倒放桌面上,防止污染瓶塞,从而污染药品.图中操作错误但不会引起安全事故.故不可选;
B、点燃酒精灯时,应用火柴点燃.如果用燃着的酒精灯去点燃另一个酒精灯,会引起酒精失火,造成危险,图中操作错误会引起安全事故.故可选;
C、取用块状固体时,先将试管横放,用镊子把固体放在试管口,再让试管慢慢地竖起来.图中操作错误但不会引起安全事故.故不可选;

D、过滤的液体应由玻璃棒引流进入漏斗.图中操作错误但不会引起安全事故.故不可选;

故选B.

阅读理解

阅读下列短文 ,从每个小题所给的选项中选出最佳答案。

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单项选择题