Helen finds ______ difficult to climb to the top of the mountain in an hour. A. that B. this C.it
I ________ a letter from him this morning. I felt very excited.
Remember to ________ the lights before you leave the classroom.
We plan to ________ a short play on Teachers’ Day. 。
________ can make people healthy.
Go to bed early and sleep well. You can work ________ tomorrow morning.