Is the man over there Adam?
It ____ be him. He has gone to Hong Kong on vacation. ( )
A.mustB.can'tC.mustn't
Students ________ play with fire in the classroom. It’s quite dangerous.
mustn’t
must
couldn’t
could
I began to teach ________ English when I was twenty-two years old.
they
their
theirs
them
Would you like to go to the open-air concert at school? It’ll start in ________ hour and ________ half.
an; an
a; an
an; a
a; a
—Could you please tell me ________?
—Next Sunday morning.
when we will go to Gupo Mountain
when will we go to Gupo Mountain
why we went to Gupo Mountain
why did we go to Gupo Mountain
After the boy’s homework ________, he went out to play.
finished
finishes
was finished
is finished