21 To succeed in a difficult task ,______________.
A) Persistence is needed B) Persistence is what you need
C ) One needs to be persistent D ) A persistent nature is needed
22 According to a new study by a British’s university , learning ______ second language can lead to ________ increase in your brain power.
A) a ; the B) 不填；the C）a ；an D）the ；an
23 With the help of the firefighters ,the workers managed to escape from burning mine , ___________.
A )hungry and frightened B)hungrily and frightening
C )hungry and frightening D) hungrily and frightened
