It is necessary _____ something to protect our environment.
#50188
A
do
B
to do
C
does
D
doing
推荐题目
It’s _____ turn _____ now.
#50480
A
you; read
B
your; read
C
your; to read
D
you; to read.
Mum allowed me _____TV last evening.
#49057
A
watching
B
watched
C
watch
D
to watch
Don’t forget ________ the lights before you go to bed.
#49236
A
turn off
B
turning off
C
to turn off
D
turns off
--- It’s too hot. Would you mind _____ the door?  --- ______. Please do it now. 
#50610
A
to open ; OK
B
to open ; Good idea
C
opening ; Of course
D
opening ; Certainly not