Teaches-----------sometimes is so tangled, teaches the time not to mention the question, seems to understand very much, finally again to pester you! That's CTMB.

A full-hearted teaching B

A few minutes later ... B "all understand."

b After a few minutes, and then call you, (walk over, hello, I have a question, can you help me to answer?) Do not delay you how much time,)

A has taken a distance, thinking has been on other things, become good impatient. (see a euphemism for a request or listen to B.)

Last B indefinitely

Result------------------teaching of failure

Teaches-----------sometimes is so tangled, teaches the time not to mention the question, seems to understand very much, finally again to pester you! That's CTMB.