It suddenly occurred to him __________ he had left his keys in the office.
Customers are asked to make sure that they______ the right change (零钱) before leaving the shop.
E-shopping, when properly , can save us a lot of time and energy.
---Where is your new home now?---In the new developed zone. But I ______downtown for five years.
Getting off the bus, she found her hand bag ________.
It's necessary that measures _____ at once to help people understand global warming is affecting our life to an increasingly high degree.