If you had followed my advice just now, you would be better now.
If you had studied hard before, you would be a college student now, and you would graduate from a college in four years’ time. 如果你以前努力学习的话，你现在是大学生了，四年后你就可以从一所大学毕业了。
在条件句中可省略if, 把were, had, should提到句首 , 变为倒装句式。如：
If I were at school again, I would study harder.
→ Were I at school again, I would study harder.
If you had come earlier, you would catch the bus.
→ Had you come earlier, you would catch the bus.
新概念英语视频教程If it should rain tomorrow, we would not go climbing. → Should it rain tomorrow, we would not go climbing. 要是明天下雨，我们就不去爬山了。注意：若省略的条件句中的谓语动词是否定形式时，不能用动词的缩略形式。如：我们可以说：Were it not for the expense, I would go abroad now. 但不能说：Weren't it for the expense, I would go abroad now. 3．用介词短语代替条件状语从句。常用的介词有with, without, but for。如： What would you do with a million dollars? ( = if you had a million dollars) We couldn't have finished the work ahead of time without your help. ( = if we hadn't got your help) 4．含蓄条件句 有时为了表达的需要，在虚拟语气中并不总是出现if引导的条件句，而通过其他手段来代替条件句。 I was ill that day. Otherwise, I would have taken part in the sports meet. (副词) He telephoned to inform me of your birthday, or I would have known nothing about it. (连词) A man who stopped drinking water would be dead in about seven days. （定语从句） I might have given you more help, but I was too busy. (连词) Everything taken into consideration, they would have raiser their output quickly. (独立主格结构) 1．Many a boy and (many a) girl ________ the same mistake.A．is made B．are made C．has made D．have made2．A number of experts ________ today that the number of acupuncture points ________ the same as the number of days in a year.A. claims; are B. claim; is C. claims; is D. claim; are3．He is the only one of the students _________ able to speak both English and Japanese well.A. who is B. who are C. that is D. that are4．The number of traffic accidents that _____ in developing countries _________ increasing.A. happen; is B. happen ; is C. happens; are D. happen; are2．B【解析】试题分析：考查主谓一致。句意：几个专家今天声名针灸的数量与一年的天数相同。第一空的主语是experts，；第二空的主语是the number，可知选B项。考点：考查主谓一致3．A【解析】试题分析：此处先行词是the only one，关系代词who指代先行词在句中作主语，故谓语动词要和the only one保持一致，使用单数形式。故选A.考点：考查主谓一致。4．A【解析】试题分析：考查主谓一致。本句中定语从句that happen in developing countries修饰先行词traffic accidents，因为该先行词是复数名词，所以定语从句中使用复数谓语动词。第二空是主句的谓语动词，本句的主语是the number，该短语做主语的时候，谓语动词使用单数形式。句意：在发展中国家中发生的交通事故的数量正在上升。故A正确。考点：考查主谓一致