—I have never been to the Great wall. —If you have an opportunity _______ there, you must take it.
—Do you often help your cousin with his English?—No. He learns English _______.
The girl is only two years old. She is _______ to go to school.
My sister is only three years old. She can’t take care of _______.
—Did Alice sleep well last night?—No, she didn’t. She didn’t go to bed _______ 12 o’clock last night.
—Would you mind _______ in the classroom?—Sorry, I won’t do that again.