—How many students are there in the classroom?
—_____. I don’t know where they have gone.
| A．No one. | B．None. | C．Nobody. | D．Nothing. |
David finds ＿＿＿ difficult to communicate with his parents
A.one B.it C.this
My cousin Mary was born ＿＿＿ a singing voice.
A.from B.in C.with
--How do you learn English?
--I learn English ＿＿＿ practicing conversations with friends.
A.on B.by C.in
—You look very worried. ________ ?
—My mother suddenly got ill yesterday.
| A．Can I ask a favour? | B．Hoe do you do? |
| C．How are you? | D．What’s up? |
I found _____ necessary to save energy and protect the environment.
| A．that | B．this | C．it | D．one |