使用1211灭火器操作时,禁止将灭火器()或颠倒使用。
A、水平
B、垂直
C、倾斜
参考答案:A
______with the size of the whole earth, the biggest ocean does not seem big at all.
A.Compare
B.Comparing
C.To compare
D.Compared
近交系的近交系数应大于()。
A.0%
B.5%
C.8%
D.9%