附着升降脚手架的防倾装置必须与建筑结构、附着支撑或竖向主框架可靠连接，应采用（）。
A.绑扎连接
B.螺栓连接
C.钢管扣件连接
D.碗扣连接
参考答案：B
In the meeting, the professor expressed his thanks for the aid he _________ from his students.
A．received
B．was received
C．have received
D．had received
搅拌机齿轮啮合不正常，可导致减速器出现异响，可尝试用（）办法解决。
A.调整齿轮轴向间隙
B.更换齿轮
C.调整齿轮轴线
D.更换齿轮轴
