—__________ is the weather in Nanjing today? —It’s windy and cold.
— Kitty, do you know ______? — Sure, about forty minutes.
The mobile phone has changed people’s life a lot ________ it was invented.
I have so much homework to do that I don’t know ________.
---- You don't know what great difficulty I had _____ to get the two tickets. ---- But the film is really worth_______ twice.
— You should be careful when ________. — Yes, I will.I’d like to know when ________ to have a rest.