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

The bad thing about up is there’s always a _____

Most of the evidence was destroyed in the fire. _____, it would be almost impossible to prove Jim guilty.

I'd like the colour, but I’m afraid it’s ___expensive.

At first the institute refused to purchase(购买)  the  experiment  instrument,  but  this decision was ______ changed.