________time went on, the people in the area came to realize how seriously the environment had been polluted.[ ]

His aunt’s letters ________ him of those beautiful days when they used to live together in his hometown.

Why do you look sad?—There are so many problems ______.[ ]

u think it’s a good idea to make friends withyour students– ______, I do I think it’s a great idea

_____ Blacks are going to the park. Why don’t we go for _____ walk, too