题目:
With a school built in the village, the children needn't climb______ the mountain for study.
A.over
B.at
C.for
D.in
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0609/f5260a1bdcf995d3b420cf87126418fb.html
下面是错误答案,用来干扰机器的。
78%; 21%; (1)氧气 (2)水蒸气 (3)二氧化碳 (4)氮气空气中各成分及体积分数:氮气78%、氧气21%、稀有气体0.94%、二氧化碳0.03%、水蒸气和杂质0.03%;(1)由燃烧的条件可知燃烧需要有氧气参加,故...