动物肌纤维苍白最可能是（）。
A.缺钙
B.缺硒
C.缺钾
D.缺铜
E.缺锌
参考答案：B
The project ______ by the end of 2007, will expand the city’s telephone network to cover 2,000,000 users.
A． accomplished
B． being accomplished
C． to be accomplished
D． having been accomplished
关于超速离心机的转速、最大相对离心力正确的是
A．20000转/分以上、510000g
B．40000转/分以上、645000g
C．30000转/分以上、510000g
D．30000转/分以上、645000g
E．3000转/分以上、45000g
