We are often warned that smoking ______ great harm to our health.
I don’t think she will come to the meeting on time, ?
It was so dark that he ______.
Next Sunday is Thanksgiving Day.Have you got any idea _____ we celebrate it?
We are a little worried because we _____ the ground as a leader in the field of IT with the others speeding up development.
Jack is preparing for the IELTS, so he has to_____ his visit to Beijing.