定期的

Water should be regularly chlorinated in public swimming baths to keep it pure.

公共游泳池水应使用氯气消毒,以保持干净。

In fact the level of compression created within a regular pulsejet engine is very low, even by automobile standards.

事实上范围内pulsejet引擎创建压缩程度很低甚至汽车标准。

Britain's best periodical art magazine.

英国最好出版艺术杂志。

Trees of the family Dipterocarpaceae dominate the canopy and emergent layers of the hyper-diverse, aseasonal, humid lowland tropical forests of Southeast Asia.

以龙脑香科植物为主东南亚热带雨林有一非常特别现象，不大开花现象。

A life insurance company contract that pays periodic income benefits for a specific period of time or over the course of the annuitant's lifetime.

在特间额支付款项。指在约时间内，按年度支付相等金额款项。例如，保险公司每年年金、退休金等。