喷油泵的主要作用是定时、（）地经高压油管向各缸的喷油器周期性地供给高压燃油。
参考答案：定量
对称性社会互动
________ (,) the proposal concerning health food production was rejected for the lack of fund required.
A．On the whole
B． Hopefully
C．Much to our regret
D．What delights us most is
