_____ the help of my English teacher, I can speak English easily.
–You can’t imagine _______ great fun chatting online is.– Really? But it may cause you a lot of trouble.
One of the most interesting places in Hangzhou ________ are often visited by foreigners is the West Lake.
–Tom, you didn’t come to my party last night?– I ________, but my mom hurt her back and I had to look after her.
Their school looks quite different from _______ ten years ago.
We must try our best to stop pollution ______ a low-carbon(低碳)life.