单项选择题
A stopper used in securing the ground tackle for sea that consists of a grab attached to a turnbuckle is a（）.
A.riding pawl B.buckler C.devil's claw D.locking ring
单项选择题 A stage should only be rigged（）.
单项选择题 A snatch block is a（）.
单项选择题 A shepherd’s crook is used to（）.
