They volunteer________at the local hospital．
A．to work
B．working
C．work
D．to working
That boy looks very unhappy．Let’s________．
A．to cheer up him
B．to cheer him up
C．cheer him up
D．cheer up him
His sister usually helps him________his homework．
A．doing
B．do
C．does
D．to doing
(2013苏州)—Your tea smells great！
—It’s from India．Would you like________？
A．it
B．this
C．some
D．little
(2013菏泽)The World Health Organization has given some advice on________to protect us from being infected(感染)with H7N9．
A．how
B．what
C．where
D．when
改为同义句
Each of the students in the class has been to the Great Wall．(改为同义句)
________ ________in the class has been to the Great Wall．
