用作消毒的化学物质称为消毒剂。
参考答案：对
古代经常说姑娘豆蔻年华，那是指的多大呢？（）
A.12
B.13
C.14
D.15
No matter _____ great progress you have made in your studies, you should continue to work hard.[ ]
A. what
B. how
C. where
D. when
