2. 利用虛擬語(yǔ)氣背景進(jìn)行命題

(1)_______ he had not hurt his leg, John would have won the race.

A. If                        B. Since

C. Though           D. When

答案為A。全句使用的是虛擬語(yǔ)氣背景，if在此引出一個(gè)虛擬條件。

(2) If Newton lived today, he would be surprised by what ______ in science and technology.

A. had discovered

B. had been discovered

C. has discovered

D. has been discovered

答案為D。此題可用排除法來(lái)做。根據(jù)what與discover的關(guān)系可知，此處應(yīng)用被動(dòng)語(yǔ)態(tài)，即指被發(fā)現(xiàn)的東西，故可排除選項(xiàng)A和C；由于句子使用了虛擬語(yǔ)氣， 所以此題的迷惑性很大，許多考生會(huì)誤選B。其實(shí)，由于句中的虛擬語(yǔ)氣是對(duì)現(xiàn)的情況進(jìn)行假設(shè)（注意句中的today），而且“在科學(xué)和技術(shù)方面所取得的發(fā)現(xiàn)”指的是現(xiàn)在的事實(shí)，而非假設(shè)，所以此處要用現(xiàn)在完成時(shí)，而不能用過(guò)去完成時(shí)。