单项选择题
Old Chinese are not used to buy things on ______ and are likely to save as much money as possible.
单项选择题 You should have put the milk into the ice-box, I expect it ______ undrinkable by now.
单项选择题 I understand ______ preparation that staff must put in under pressure to meet the deadline.
单项选择题 You should have your eyes tested every year in case the ______ of your spectacles need changing.