问题详情

How should you signal the crane operator to raise the boom and lower the load?().


A、Extend arm with the palm down and and hold this position rigidly

B、Place both fists in front of the body with the thumbs pointing outward each other

C、Clasp hands in front of you body

D、Extend arm with the thumb pointing up, and flex the finger s in and out for as long as the load movement is desired

时间:2022-01-10 13:30 关键词: 航海英语综合练习

答案解析

D