下列说法正确的是[ ]
A.干冰可用于人工降雨
B.煤炉上放一壶水可以防止CO中毒
C.铅笔芯的主要成分是金属铅
D.只能用红磷来测定空气中氧气的含量
答案:A
8750mL=______L
8.09m3=______dm3=______L.
After a long journey, we all felt very tired and so we decided to ____ . [ ]
A. take our time
B. take our ease
C. take it easy
D. take our place