I can think of many cases ______ students can’t write a good article though having a large vocabulary.

______ catch the early bus, John got up early today.

After retirement, learning a musical instrument may be harder than ______ when you were a kid.

We cannot figure out ______ quite a number of students were infected with the flu.

As is often said, a friend is to man_____ water is to fish.

Can you tell me_____ difficult the exam turns out to be? 

Tom showed me his new cell phone, _______  was small but it could change colors in different weather.   

Today the public is much concerned about the way _______ .

― I’m afraid I have to give it up.
― Don’t be discouraged. Remember ______ sticks to his work will succeed one day.

A net is to a fisherman ______ a gun is to a hunter.