I really can’t believe such a learned man has made so silly a mistake.- Don’t you know_______ sense is worth more than knowledge

Can you play chess— No, but I can play ________ piano very well．

The monument was built in honor ofthe explorer who was believed _____ the river.

It was last year _____ I visited the museum _____ you had visited

The doctors has_________ a new idea on the treatment, which is well thought of by his companions.