图18-3-7所示锥摆。已知OM=l,如质点M绕z轴的角速度为ω,则摆角α为()。
A.A
B.B
C.C
D.D
参考答案:C
—The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?
—____ my students have a try?
A.Shall
B.Will
C.Could
D.Should
矿物在水化过程中结合了一定数量的水分子进入物质中,会引起体积收缩。