平流层中空气沿铅垂方向的运动较弱,因而该层气流()
A.虽不稳定但能见度较好
B.不稳定且能见度差
C.比较平稳且能见度较好
D.比较平稳但能见度较差
参考答案:C
某饮用商品的标签如图所示这里的硒、锶、锌、钠等是指( )
含有****(mg/L)
硒:0.013
锶:0.0596
锌:0.00162
钠:18.3…
A.原子
B.分子
C.单质
D.元素
"Sandy is busy, but I can go there instead of him. " he__________. [ ]
A. replied
B. volunteered
C. answered
D. asked