1贝可（Bq）等于每秒的核衰变次数为（）。
A.1次
B.2次
C.5次
D.10次
E.100次
参考答案：A
The biggest whale is _____ blue whale, which grows to be about 29 meters long-the height
of _____ 9-story building. [ ]
A. the; the
B. a; a
C. the; a
D. a; the
小儿骨骼生长发育中
前囟关闭最迟的年龄通常为（）
A.8个月
B.12个月
C.11个月
D.13个月
E.18个月
