【题目】I wonder ______ the room is big enough or not.

【题目】—Where is my mom, dad?

【题目】When you leave, don’t forget ______ off the light.

【题目】To save more animals, we can't ________the trees.

【题目】The rules at school are useful for us, ________we have to follow them.

【题目】If you have the“ofo”app on your phone, you can get to some places________.

【题目】You need to ________teeth after a meal to keep the mouth clean.

【题目】It's very popular to travel in Thailand, but remember not to buy things made ________ ivory,

【题目】We can see _______ stars at night if there are no clouds in the sky.

【题目】The man is feeling much better now, so you _______ call a doctor.