书名：寂天新多益阅读超高分
页数：p.189 第183题 (双篇阅读)
题目：
不知道是不是需要把双篇全部文章打出来?
我先把我觉得相关的文章打出来
The bus arrives every 30 minutes,and the train arrives every 15 minutes.
Tickets for the expres train can be purchased online,while bus tickets
are only available in person.
183.According to the letter, what advantages does the train have over
the bus?
(a)They run more frequently.
(b)Discounts are available.
(c)Refreshments are sold on board.
(d)Tickets can be purchased online.
疑问：第2句可以看出(d)为正解,这是没问题的
问题是(a)错在哪里?
附上争议点部分的解答翻译
The bus arrives every 30 minutes,and the train arrives every 15 minutes.
公共汽车每30分钟一班,而火车则是每15分钟一班
(a)They run more frequently. 班次较频繁
我的疑问是从我附上翻译的这句来看,(a)我也认为是对的,
唯一的破绽是(a)选项主词用they
让我猜测可能就是错在这里? 但又不能肯定
烦请板上先进解惑,感激不尽