The fact has worried many scientists_______ the earth is becoming warmer and warmer these days.
The boy who had broken the rule avoided _________.
Whenever you have questions in class, first you should _____ your hand , then _____and ask with the permission of the teacher.
----Why are you late ? ----sorry, the bus I took ______ the mud for half an hour, so I had to walk here.
With time _______, we didn’t do enough preparation for this examination.
I want to have a talk with you ,Bob .Is three o’clock tomorrow afternoon_____ to you ?