问几个英文语法的问题In his memoir,Baker tells stories about the time before he entered high school,when he is having to deliver newspapers to the huge estates and mansions that lined the riverfront.这个句子里的about the time为什么

问几个英文语法的问题In his memoir,Baker tells stories about the time before he entered high school,when he is having to deliver newspapers to the huge estates and mansions that lined the riverfront.这个句子里的about the time为什么
问几个英文语法的问题
In his memoir,Baker tells stories about the time before he entered high school,when he is having to deliver newspapers to the huge estates and mansions that lined the riverfront.这个句子里的about the time为什么可以这样说?不是应该at the time才对么?另外,is having to 有什么语法上的错误么?
To the disappointment of the crowd,neither the president nor any of his aides were able to attend the ceremony
这里的were怎么就错了呢?不是说neither nor后面的动词要就近么?不是离aides最近么?为什么不是were?
As a freshman becomes adjusted to the routines and demands of college life,one may realize that the rigors of high school were good preparation.
这里的one不可以这样用么?那么one真正的意义和用法是什么?另外这里的were不是与全句时态不符么?
According to some demographers,the number of United States citizens aged 65 or older is likely to rise to 87 million by2050.
这里的话,or older这样的表达哪里错了啊 不能这样说么?
When Doris Lessing published the Golden Notebook in 1962,it instantly established herself as one of the most important literary voices of her generatons.
这里的话我知道it不可以指代前面一件事情,但是它说这里it错了的话为什么不可以理解成是代指那本书呢（也就是那本书让那个作则得到了什么的荣誉什么的）

问几个英文语法的问题In his memoir,Baker tells stories about the time before he entered high school,when he is having to deliver newspapers to the huge estates and mansions that lined the riverfront.这个句子里的about the time为什么
1、从语法上来说的话,换成at the time也是可以的.但这是别人的文章,换了就不符合作者原意,这里已经不是可不可以而是合不合适的问题了.文中about 是指大约之意,表示对那个时间回忆的模糊性,不敢肯定.
2、 any of his aides当成一个整体来看,是单数,指没有一个支持者（any再此为任何一个）,故为单数.靠近原则是正确的.
2、one有很多用法,（如：不定代词、数词等等）,此处为代词,但问题是要联系上文,one用来指代上文出现的某类物中的一个.是否上文已经出现one的所指,如果没有就是错了.至于were,这个句子的当时是大学而他后半句说rigors of high school 是故去的高中生活,所以是过去时.
4、这题是思维问题了.句子本意是“美国65岁及以上”而不是“65岁或者65岁以上”,一个or只差就差这么多.说话者不可能是后面的意思,讲的是人口老龄化问题.所以应该改为 “ and older"
5、这个it 在这里就是有歧义,术语上叫（ambiguity),指称不明,会给读者造成困惑的,在句子中it 是指那本书还是指Doris出版这本书这件事情.这是其一,问题二还要看上文的指代关系,上下句的指代不能乱成一团,要一脉相承,才能是文章通顺连贯逻辑合理,术语上叫cohesion.刚好是我之前做过的论文,多啰嗦几句,