Personally I think the ______ Andrew drew from his simple experiment is not scientific.

A new __________to teaching English is being used here, and it has proven to be very helpful to the students. 

—Can you help me with this problem?—It's beyond my __________.I didn't work it out, either.

As is well－known，the brain performs a very important ________，which controls the nerve system of the body.

Although it is not our normal _____ to give credit, this time I think we should consider the matter more closely.