We have to admit that the biggest___________ facing the ecosystem is limited resources and the worsening environment.
#12389
A
mission
B
challenge
C
scale
D
contribution
推荐题目
Mom believes that those words put to paper two centuries ago really _____ something.
#12780
A
mean
B
represent
C
tell
D
say
Spectators of horse racing come primarily to ________ the result of each race.
#12071
A
predict
B
gamble
C
bet
D
bet upon
You had better ________ some time every day for sports so that you can keep yourself energetic.(2012·福建)
#11538
A
set aside
B
take up
C
put away
D
give out
Population experts say that by 2050 the world will have about 2 billion people aged over 60,____as today.
#14137
A
as three times
B
three times as many
C
three times many
D
three times many as
(2013·辽宁五校一模)The little child ________ go out alone at night, so he ________ walk in the dark that night.
#11322
A
doesn't dare to; dared not to
B
daren't to; didn't dare to
C
daren't; dared not
D
doesn't dare to; dare not