To keep healthy, Professor Johnson ______ cycling as a regular form of exercise after he retired.
#71817
A
took up
B
caught on
C
carried out
D
made for
推荐题目
Tom opened a bookstore in NO.3 Middle School, but        it closed down.
#65703
A
ever since
B
just then
C
before long
D
soon after
—Why are you so nervous?—To our great surprise, we found       by the strangers.
#72551
A
we monitored
B
ourselves monitored
C
us to monitor
D
ourselves monitoring
As the crowd rushed towards the gate, several people got______.
#70636
A
knocking down
B
knocked off
C
knocking on
D
knocked over