The government of the United States began at once toinvestigate the case ______ a lot of students were killed.

You can’t believe how terrible the fire is __________ you see it with your own eyes

―Would you like to visit the new museum with us this Sunday―____________, but I will have to work then.

We can use QQ to talk with each other on the Internet.— Really Will you please show me __________ it.

I was on the point of going to bed ________ MrZhang rang