All of us know, color-blind people often find it difficult to __ between blue and green.

There is ______ little information about him that we have ______ much difficulty finding him.

Ihopemyfather____askmeaboutmymarks.

—Have you finished the work?

—Not yet, but no matter how hard it is, we'll keep ___ until we make it.

Mr. Green is used to_________ two apples after lunch every day.