________is the existence of a large number of different kinds of animals and plants which make a balanced environment.

Toxic chemicals in the air and land have driven many species to the _____ of extinction.

There is one person to ________ I owe more than I can say.

He managed to keep his job ________ the manager had threatened to sack him.

Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction.

Because his sickness, he didn’t take part in the English competition held last Sunday.

Our project was successful ________ its practicality.

Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction.

Dreaming, like all other mental processes, it is a product of the brain and its activity.

After a good night’s sleep I woke up feeling as fresh as ________ and eager to start a new day.