When he came back, he found the bag he had ____ over the seat was gone.
The drill in Antarctica dragged on slowly because of lack of money, equipment breakdowns, environmental _____ and severe cold.
Can you show me a case this phrase is often misused by Chinese students, Mr. Brown?
—What on earth makes you apply for the position as a guide? —This is the job that I .
The students entered the classroom,smiling and________,and ______ down to have their lessons.
He kept a little notebook, in which the names and addresses of his friends.