they put their hands___(back.up,.in front,down)

题目

they put their hands___(back.up,.in front,down)
后面and got ready to shake hands with them

答案

they put their hands down.
他们放下了他们的手.
put down
v.
放下,
如果后面是and got ready to shake hands with them的话
就应该选put up了,put up是“举起,抬起”的意思.
整句话意思是：他们抬起他们的手准备和别人握手.