转速是指泵轴每分钟旋转的次数,其单位是()。
A、转/秒
B、转/分
C、米/秒
参考答案:B
Washington, a state in the United States, was named ______ one of the greatest American presidents. [ ]
A. in favor of
B. in need of
C. in search of
D. in memory of
窗体由多个部分组成,每个部分称为一个 “【 】”。