The only system I know ____ will help you remember what you have heard at a lecture is the system of keeping notes.

In China, the number of cities is increasing _____development is recognized across the world.

Since the recent river pollution in Shanxi Province , people ____ more and more attention to the water quality

It’s really cold here. I have never experienced such terrible weather in my life. [ ]

Not until the train pulled into the station thathis suitcase was gone.