The keeper of the spring cleared away the leaves and branches, and wiped away the silt(淤泥) that would _______ have choked and polluted the fresh flow of water.

Death toll from Typhoon Haiyan in the Philippines _______ 3,637, after the strongest storm this year destroyed the central part of the country on Nov. 8, 2013.

To protect the environment, the local government has put up a lot of ______ to warn the citizens not to litter the ground.

Corruption is _______ problem in countries across the world, with developing countries often believed to be more serious, although there is no evidence to suggest this is _______case. 

— How much influence will your time in high school have on the rest of your life?— It ______ be quite a lot, or perhaps only a little. 

If you don’t learn to think _____ you are young, you may never learn.

I still don’t know ______ she’s planning to come to my birthday party or not.

— Could you give _______ an introduction to the new machine?— Of course. I will tell you how to use it. 

 These days, it seems that we rely on the Internet often, and we couldn’t possibly live _____it. 

Up to now, no one has come up with a（n）       explanation of why dinosaurs died out, and it remains a mystery．

The green-hand cook        the soup by putting in too much salt accidentally．

With high technology introduced, the average output of the factory is        increasing．

Before we end this program, let's take a          at the sports news briefly．

The heart is a（n）       organ,  It is of absolute  importance to our body and life．

----Did you finish reading that long novel? ----No, I ran out of ______. It’s too long and I only completed half of it.

He tried to join the army but was _____ because of poor health, which made him depressed. 

The teacher’s encouragement doesn’t ______ mean your progress, so you should try your best as well.

Long term of hard work and lack of sleep finally ______ her health.

The familiar English song ______ me of the happy days l spent in Scotland several years ago.

As a photographer, I’m used to keeping the camera easily      on an outing.