电动单梁起重机的起重量一般为（）。
A.10~100kN
B.10~50kN
C.10~200kN
D.10~25kN
参考答案：B
After studying in America for seven years, Lily’s brother ______ his job as a doctor in Japan.
A．took up
B．took over
C．took in
D．took on
什么是冷裂？什么叫热裂？各自的特征如何？
