—Leaving for Beijing?— ________. 

It is______ acknowledged that he is honesty.

It is ________ that he has been addicted to the drugs and has difficulty quitting it.

As is often pointed out, knowledge is a two-edged weapon which can be used ________ for good or evil．

---- Do you think it's a good idea to make friends with your students? ---- _____ , I do．I think it's a great idea．