—People ________ wear helmets(头盔)when they ride e-bikes according to the traffic rules.
—Yes. Or they will be punished.
must
can
may
There are so many kinds of pens in the shop ,I can’t decide ______.
The young man used to _____to work, but he is used to ______to work now.
---Please turn off the light. ---OK, Mom. I won’t leave the room _____ the light _____.
--- He went to see the man who was in hospital yesterday. --- ____________.
_he tried many times, he still couldn’t move the heavy box.