Scientists have found evidence ________ global warming caused the world's first horses to become smaller nearly 50 million years ago.
Mother ______ him not to smoke, but he wouldn’t listen.
______ more and more trees cut down, many animals and insects are dying out.
Could it be in the place ______ we visited yesterday ______ you left your book?
Although the number of competitors ___ limited, a number of our classmates ___ eager to take part in it.
We don’t need to do ___ extra work this evening. The day’s work was almost at ____ end now.