____ __do you go to the library？
Twice a week．（ ）
A．How soonB．How longC．How oftenD．How far
______to turn off all the lights when you go out．（ ）
A．RememberB．To remember
C．Remembering
Could you tell me ______you will start your vacation？
In a week．（ ）
A．howB．whatC．when
Mum， I'd like a cup of coffee．
Dear， why not drink some water？It's ______than coffee．（ ）
A．healthyB．healthier
C．the healthiestD．healthy
Chinese ______by more and more people around the world．（ ）
A．is spokenB．speakC．speaking
Did you see the sign "No Swimming"？You ______swim in this river．（ ）
A．needn'tB．mustn't
C．don't have to