除赤道外，两点间的东西距绝对值比两点经差绝对值（）。
A．相等
B．小
C．大
D．视北纬，南纬而定
参考答案：B
—Do you know ______ he is going to stay in Shenzhen?
—Sorry, I don't know. Maybe a few weeks, but I'm not sure. [ ]
A. when
B. how long
C. what time
D. how soon
烟气中的残氧量越高，说明炉气呈（）气氛。
