You should have put the milk into the ice-box, I expect it ______ undrinkable by now.

I understand ______ preparation that staff must put in ...

单项选择题I understand ______ preparation that staff must put in under pressure to meet the deadline.

You should have your eyes tested every year in case the...

单项选择题You should have your eyes tested every year in case the ______ of your spectacles need changing.