转基因技术是一项先进的生物科学技术，这一点已在世界范围内取得共识。美国是转基因技术

How should you signal the crane operator to stop？______.

A.Place both fists in front of your body with thumbs pointing pointing outward

B.With both arms extended out and palms down, move arms back and forth

C.Extend arm with the palm down and hold this position rigidly

D.Clasp hands in front of your body

How should you signal the crane operator to dog everyting？______.

A.Place both fists in front of your body with thumbs pointing toward each other

B.Clasp hands in front of your body

C.Extend arm with the palm down and hold this position rigidly

D.Extend arm with the thumb pointing up, and flex the fingers in and out

How should you signal the crane operator to lower the boom？______.

A.With arm extended and fingers closed, point thumb downward

B.With arm extended downwards and forefinger pointing down, move hand in small horizontal circles

C.Extend arm with the palm down, and hold this position rigidly

D.With hands clasped in front of your body

How should you signal the crane operator to raise the boom？_________.

A.Extend arm with the thumb pointing up and flex the fingers in and out

B.Place both fists in front of the body with the thumbs pointing upward

C.With forearm vertical and forefinger pointing up，move hand in small horizontal circles

D.Extend arm with fingers closed and point thumb upward

How should you signal the crane operator to hoist ________．

A.With forearm vertical and forefinger pointing up，move hand in small horizontal circles

B.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles

C.Extend arm with fingers closed and thumb pointing upward

D.Place both fists in front of body with the thumbs pointing upward

How should you signal the crane operator to lower the boom and raise the load ________．

A.Extend arm and point finger in the direction to move the boom

B.Extend arm with thumb pointing downward and flex fingers in and out

C.With forearm vertical and forefinger pointing up，move hand in small horizontal circles

D.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles

How should you signal the crane operator to move slowly ________．

A.Use one hand to give any motion signal，and place the other hand motionless in front of the hand giving the motion signa

B.Extend arm with the thumb pointing up，and flex the fingers in and out for as long as the load movement is desired

C.First tap your elbow with one hand and then proceed to use regular signals

D.First tap the top of your head with your fist and then proceed to use regular signals

A.raise the boom

B.raise the hook

C.raise the boom and hook

D.check the boom stop

During which condition should be operator of a pedestal crane shutdown operations？

A.Bunkering

B.High winds

C.Potable water spill on deck

D.More than 3°list

During which condition should the operator of a pedestal crane shutdown operations ()

A.Lightning in the vicinity

B.An approaching squall line

C.A fire on the pier

D.All of the above