—Using public chopsticks ______ necessary when eating with others.
—That’s right.
is
are
was
were
Must he sing the song in English?
No,he____.( )
needn't
can't
mustn't
____fine weather we have today!( )
What a
How
What
I wish you a happy National Day!
_____.( )
The same as you
Thank you
The same to you
It's already tens of years____the world's population reached five billion.( )
before
after
since
We must remember____.( )
what our teacher said
what did our teacher say
what has our teacher said