18. It was ______ back home after the experiment.
I’m not sure whether I will have anything else to do this evening._____, I will try every possible means to come to your birthday party.
My toothache is killing me.I _____ it _____ away.But now it’s getting worse and worse.
---The exam starts at 9:00 tomorrow morning.---___________ I fail to arrive there on time?
_____ on May Day, the Shanghai Expo has attracted tens of thousands of visitors around the world every day.
With the moonlight keeping them ________, the tourists climbed over the mountain without a guide.