--- Smoking is bad for your health. ---Yes, I know. But I simply can’t ___.
A.give it up B.give it in C.give it out D.give it away
In that school, English is compulsory for all students, but French and Russian are _______.
A.special B.regional C.optional D.original
Teachers have to constantly update their knowledge in order to maintain their professional ________．
A.consequence B.independence
C.competence D.intelligence
____ making decisions, the human brain cannot be compared with the computer because in the long process of evolution the slow pace of life didn't require such an ability of the human brain.
A. On behalf of B. In contrast to
C. In salute to D. In terms of
Either side seems to have a(n) _________ position; there are still many uncertainties on this issue.
A. ambiguous B. delicate C. explicit D. confidential
Though scientists get closer to understanding why we age， the reason for different aging rates among individuals remains only __________ understood．
A.concretely B.thoroughly
C.vaguely D.flexible
