There is a note pinned to the door______ when the shop will open again.
A. saying B. says
C. said D. having said
Clearly and thoughtfully________, the book inspires confidence in students who wish to seek their own answers.
A. writing B. to write
C. written D. being written
Last night, there were millions of people _______ the opening ceremony live on TV.
A.watch B. to watch
C. watched D. watching
There are still many problems ______ before we are ready for a long stay on the Moon.
A. solving B. solved
C. being solved D.to be solved
Group activities will be organized after class _______ children develop team spirit.
A. helping B. having helped
C. helped D. to help
The producer comes regularly to collect the cameras _______ to our shop for quality problems.
A. returning B. returned
C. to return D. to be returned