小组工作又称团体工作，它是以（）为单位的助人工作方法。
A.个人
B.小组
C.集体
D.社会
参考答案：B
20．It was four o'clock in the afternoon_____he and his grandpa reached the museum in Guanghan, _____an official warmly received them.
A．that; where
B．when; that
C．when; where
D．that; when
局部剖面视图属于（）。
A.剖视图
B.剖面图
C.三视图
D.左视图
