有一读者问：
(1)We did not expect to be staying in first-class hotels, because this is an economy tour.
该句中为什么用现在一般时 is? 全句不是在叙述往事吗？
句中 because 从句之所以用现在一般时 is 是因为这一从句所表的是一客观事实，并没有什么时间概念，其含义是经济旅游者总是不住一流旅馆的。这种在叙述往事时间或插入一些表示客观事实或一般规律的现在时态的情况并不罕见，再如：
(2)I saw some small tablets in a very thin tape like a straw you drink from.（现在一般时 drink 表一般规律）
(3)Though the hotel is slightly run down it was clean and the staff could not have been more helpful and friendly.（现在一般时 is 表客观事实）
(4)My parents came to see me, to see how I live and it put their minds at rest. （现在一般时 live 表经常情况）
有时亦可插入现在进行时或现在完成时，如：
(5)He had just reached the time of life at which “young” is ceasing to be the prefix of “man” in speaking of one.（插入现在进行时 is ceasing）
(6)She had the tense nervousness of those who have had hard times from birth.（插入现在完成时 have had）
插入表客观事实的现在一般时的情况也不仅限于叙述往事时。它也可以插入叙述未来事情时，如：
(7)I'll show you how the machine works .（现在一般时 works 表经常情况）
(8)The largest denomination you will see is the one hundred-dollar bill. However, many people do not like to carry a bill of this size in their pocket. （这两句话是对将要到美国去的人讲的。现在一般时 is 和 do not like 都表经常情况）
