These diagrams are especially helpful when we have a concrete problem ______ at hand.

The 8.8 quake in central Chile caused widespread damage, destroying lots of buildings and hundreds of thousands of people_______ .

O'Neal works hard．He is often seen _______ heavily before his teammates have even arrived at practice．

There are many tall old trees____ in and around our school.

Although ________ the 2012 Nobel Prize in Literature, Chinese writer Mo Yan does not consider himself to be a “literary master”.