英語語法 關(guān)于If引導(dǎo)的條件狀語從句或虛擬語氣
If i were on the spot that day,___________________________.
A.I should be able to prevent the disaster from happening.
B.I would have been able to prevent the disaster from happening
選擇那個(gè)?標(biāo)準(zhǔn)答案是B.
這里使用的是虛擬語氣嗎?如果是,那不是應(yīng)該使用If i had been on the spot that
這是我網(wǎng)上找到的解釋,擔(dān)不是非常理解:
7.條件從句與結(jié)果主句所表示的時(shí)間不一致
(1) 當(dāng)條件從句與結(jié)果主句所表示的時(shí)間不一致（如一個(gè)是過去發(fā)生的，一個(gè)是現(xiàn)在發(fā)生的）時(shí)，虛擬語氣的形式應(yīng)作相應(yīng)的調(diào)整。如：
If you were in better health,we would have asked you to come.
如果你身體好一些，我們?cè)缇驼?qǐng)你來了。
If we had consulted him on the question yesterday,we should know what to do now.
假如昨天我們向他請(qǐng)教了這個(gè)問題，現(xiàn)在就知道該怎么辦了。
You would be much better now if you had taken my advice.假如你接受了我的意見，你現(xiàn)在就會(huì)好得多。
(2) 如果條件從句用if I were．．．，結(jié)果主句則可用任何時(shí)間的虛擬形式。如：
If I were not busy,I would have come.
假如我不忙，我就會(huì)去的。（were表過去）