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
Evidence obtained from observation and experiment is often used to _____ a scientific theory.
#4841
A
confirm
B
confine
C
conform
D
conceive
Because of ______ high demand for Type AB blood, ______ supplies of it are usually limited．
#4619
A
the; the
B
/; /
C
/; the
D
a; the
So absorbed _____ in her work that she didn’t realize I was behind her.
#4557
A
did she
B
was she
C
she did
D
she was
Jenny nearly missed the flight______ doing too much shopping.
#5027
A
as a result of
B
on top of
C
in front of
D
in need of