绘图题：试画出牵引端从动滑轮引出“2-2”（即两只双滑轮）的滑轮组示意图。
参考答案：
如图E-19所示。
It was with great joy ______ he received the news _____ his lost son would soon return home.
[ ]
A. because ; that
B. that ; that
C. because ; which
D. that;/
劳务培训目标应包括（）要素。
A.内容
B.人员
C.标准
D.资金
E.条件
