When was _____ that the general manager left for Japan?

When you read the book, you’d better make a mark ____ you have any questions.

________Mary ________ Jack is listening to the report carefully,because they are both interested in it very much.

Watching the online open courses of some famous European and American universities _______a new fashion among white collars in China over the past few months

The spokesman did not give out the details of the message, saying, “it should not be made public as it is a ______ issue”．