It's ten years since the scientist _______to discover the valuable chemical.
#13947
A
kept up
B
set out
C
took in
D
set about
推荐题目
---Your ceiling requires ________. --- Yes, I’ll have some workers _______ it 
#12235
A
mending; to mend
B
mending; mend
C
to mend; mend
D
to be mended; to mend
Don’t leave the water ___ while you brush your teeth.
#13914
A
run
B
running
C
being run
D
to run
Harry _______ golf after graduation from college.
#13325
A
took up
B
took in
C
took over
D
took down