too clever?!

"okay, I'll pass the workbook to you; please write today's day and date, and try out the first question, after you've done the first question, let me have a look. After then, you may continue the rest at home, and don't forget your coloring."
They started to do their works.
... ...
strange..., why the top students seems can't finish the work I asked them to do forever??
... (take a closer look...)
"Can't you listen? just finish the first question, and do the rest at home!!"
They were trying hard to finish all the questions; no wonder.
I was angry. Even those that were not concentrate during my lesson also can follow my instruction, why can't the top students?!! ... ... ("They are too clever.")
"Erase all the rest, I just want the first question to be done!"