when crossing the stree ,the lady __to the ground .a.falls b.fellc.has fallend.had fallen正确的是哪个,为什么其他的不对呢?

You must be careful when crossing the street.改为祈使句 Be careful when ( you are ) crossing the street. st.bernard dogs have saved the lives of travellers crossing the dangerous pass.我想问下crossing ...st.bernard dogs have saved the lives of travellers crossing the dangerous pass.我想问下crossing the dangerous pass在这句子作什么成分? when的省略用法 when crossing the street,it is nrcessary to be careful对不对 根据这篇文章提几个问题刻舟求剑Making His Mark A man from the state of Chu was crossing a river.In the boat,his sword fell into the water.Immediately he made a mark on the boat.This is where my sword fell off, he said.When the boat st The child was crossing the street when he suddenly-----[fall] to the ground. when crossing the street,the lady ------to the groundAfalls Bfell Chas fallen D had fallen Be careful when your crossing the street.这个句子错在哪,Be careful when your crossing the street.这个句子错在哪, At the crossing,when the light is red,we must_____快回答!快!在线等!~!~!~! When we are crossing the streets,we must look out_____ the traffic. at the first crossing paraphrase 'crossing the bar 初三竞赛英语,答案我知道,麻烦解释下39. The man spoke in a strange voice and I couldn’t whose voice it was. A. turn out B. pick out C. take out D. turn up43. —I always look out when crossing the st When you are crossing aroad, you must_______（注意）the traffic on both sides. he was knocked down(when crossing the street).请问括号中为什么可以这样用? Be carefully when ____ the road.A crossing B to cross C cross Be careful when crossing the road中的cross为什么加ing说清楚原因, When he was crossing the street,a bike koncked him down什么意思