(2014·山东实验中学二模)You can never be________careful，the road is icy and slippery

I visited the Purple Mountain Observatory lastSunday.—__________ Why didn’t you tell me earlier

_____ all our efforts to save the school, the authorities decided to close it

That black T-shirt which has Messi’s picture on it______be David. He admires him a lot.— It _____ be his. He prefers black to other colours.

I suggest buying her a Teddy Bear for her birthday. —_____someone else brings the same present