根据提示填空（每空一词）
They saw a big snake when they looked out of the tent. (就加粗部分提问)
____ ____they ____ when they looked out of the tent?
答案
What,did,see
知识点：特殊疑问句 动词时态：一般过去时
对a big snake提问，要用特殊疑问词what来引导。由后面的looked可知事情发生在过去，要用一般过去时，特殊疑问句要借助助动词did，实义动词用原形。所以正确的表达为：What did they see when they looked out of the tent?
略
WORD格式（
