Carbon dioxide ___ from burning fuels is the most common of the so-called greenhouse gases.
#4678
A
producing
B
having been produced
C
to be produced
D
produced
推荐题目
.By around 900 AD,there were many places in Northern Europe______the Vikings chose to live.
#4786
A
in which
B
when
C
which
D
at which
There are, of course, bad teachers as well as ________.
#4571
A
good one
B
some good
C
good ones
D
those good
______in the heart of Toronto is the Canadian National Tower, ______ is often called the CN Tower for short.
#4592
A
Located, where
B
locating, which
C
locating, where
D
located, which