not once or twice

• adj. 屡次(常常)

例句

用作形容词 (adj.)

1. Frequent failures did not affect his morale.
   屡次失败都没有使他泄气。
2. From time to time, scientists have speculated that the proton and electron charges might not be exactly equal in magnitude.
   屡次地，科学家们推究质子与电子的电荷大小可能不恰好相等。