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It is necessary _____ something to protect our environment.
#50188
A
do
B
to do
C
does
D
doing
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I saw him _______basketball with Jack an hour ago.
#49291
A
plays
B
to play
C
played
D
play
—On my way home。I saw an alien   into a shop．I stopped    photos excitedly．—Sounds exciting!
#49623
A
go，taking
B
to go，to take
C
going，to take
D
going, taking
I don’t know _____ next.
#49598
A
how to do
B
what to do
C
what can I do
D
how I can do
The robot needs _______ once a month. And we will check it for you for free.
#48844
A
to check
B
checked
C
checking
D
to checking
Lucy practiced_____ the piano last weekend.
#49905
A
play
B
plays
C
playing
D
played