根据中文提示完成句子。
1. 你最好带上雨伞，外面正下着大雨。
____________________________ an umbrella with you. It's raining hard outside.
2. 看！同学们正忙着为运动会做准备呢。
Look! The students are busy ____________________________ the sports meeting.
3. 请你递给我那本字典好吗？我想查几个生词。
____________________________ pass me that dictionary? I'd like to look up some new words in it.
4. 等风停了，再开窗户。
Don't open the windows ______________________________________________________.
5. 那道数字题真难，我用了两个小时才做出来。
That maths problem was _____________________________________________________.
