There was a hard-working student called Mary. She spent a lot of time on her ________. She studied so hard that she became ill. She couldn’t go to sleep at night. So when she ________ the next morning, she felt very tired. She couldn’t pay attention (注意) to what the teachers said in class carefully and she even did ________ in the tests.

Finally, Mary went to see a doctor. After ________ Mary’s words, the doctor said, “All you have to do is to relax and eat more ________ food like fruit and vegetables. Besides, you can try to count ________ when you are staying in bed. By the time you count to one thousand, you will be ________.”

The next day, Mary came to the hospital again. “Well,” said the doctor. “How do you ________ today?”

Mary still looked ________. “Not very well,” she said, “I tried to count one, two, three, four... up to one thousand. But when I counted to five hundred and sixty, I feel sleepy (困倦的). I had to get up and drink some ________ so that I could go on counting up to one thousand. But then I still couldn’t fall asleep.”