We usually take turns ______cleaning ,and today it is my turn ____it
We _______ on it for several hours but we have not yet reached any conclusion.
I ____ to go for a walk, but someone called and I couldn’t get away.
Salley________Beijing for Shanghai and________there ever since. You can go and pay her a visit on your way to Hangzhou.
A new technique ____ out, the yields (收成) increased by 20% .
---What do you think of my suggestion?--- Sorry. What's that? I ____ about something else.