交流电的有效值是()的0.707倍。
A.最大值
B.有效值
C.瞬时值
D.平均值
参考答案:A
New York is famous for its skyscrapers (摩天大楼), ____ has more than 100 storeys. [ ]
A. the high of which
B. the highest of which
C. the highest of them
D. which of them
下列加粗字的意义和用法大致相同的一组是[ ]
A.于 ①唐浮图慧褒始舍于其址 ②古人之观于天地、山川……往往有得
B.以 ①以其求思之深而无不在也 ②夫夷以近
C.盖 ①今言“华”如“华实”之“华”者,盖音谬也 ②盖余所至,比好游者尚不能十一
D.故 ①以故其后名之曰“褒禅” ②故非有志者不能至也