VOA常速英语:Fewer Kids Living in US Suburbs

2. valid adj. 有根据的;确凿的;令人信服的
例句：Her argument is valid.
她的论点是站得住脚的。

3. romp vi. 嬉笑玩闹
例句：Children romped on the playground.
孩子们在操场上嬉笑玩闹。

4. decade n.十年, 十年间
例句：Prices have risen steadily during the past decade.
过去的十年间, 物价一直在上涨。

5. remain v. 仍然是, 依旧是
例句：Peter has become a judge but John remains a fisherman.
彼得当了法官, 但约翰仍是个渔民。

6. absence n. 不在,缺席
例句：She never speaks ill of anyone in his or her absence.
她从不乘人不在时说别人的坏话。

7. neighborhood n. 邻近地区
例句：They live in the neighborhood of the TV station.
他们住在电视台附近。

8. enrollment n. 注册,入会,入学等的人数
例句：Middle school enrollments will peak this year.
今年中学入学人数将达到高峰。

9. sprawl n. (城市)杂乱无序拓展的地
例句：Once lovely countryside is absorbed区 by urban sprawl.
这个曾经风光秀丽的乡村在城市的无规划扩展中消失了。

10. recall vt. 回忆起, 回想
例句：I recalled that he had mentioned the problem once.
我回忆起他曾经有一次提到过这个问题。