34 This is____ a difficult problem ____ all of us can’t work it out

(2013·西工大附中模拟)　　　, I believe, and you will find Tom is very outgoing.

The biggest problem was thatthousands of travelers remained _____ outside because of the floods.

Amy thinks moon cakes are too sweet. She eats them.

Only when _____ in the afternoon _____ able to leave.[ ]