Clean water and fresh air are essential for our daily life, _______ we can’t live.
A. by which B. without which
C. that D. on which
----Tom, you’ve got an A in the final English exam. Congratulations!
----Thanks. But I never thought the result came out so fast. The papers ______ when I left the teacher’s office just now.
A. had been marked B. were still being marked
C. are still marking D. had been marking
When the audience heard the alarm, they all hurried to they thought was an emergency exit door．
A．what B．which C．where D．Who
--- We expected you yesterday．
--- I'm sorry, I you to say that I couldn't be here until today．
A．must have called B．would be calling
C．could have been calling D．should have called
He had a wonderful childhood, ________ with his mother to all corners of the world.
A. travel B. to travel
C. travelled D. Travelling
—Your colleague's spoken English is quite good, Amy．
— No wonder, as she in the USA for two years．
A.worked B. has been working
C．had worked D. has worked
