虚拟语气的例子：（大全Q118） 1.Art museums do not usually think of their collections as capital or consider the interest income that would be generated if a portion of the capital would have been invested in another form. (A) be generated if a portion of the capital would have been (B) have been generated if a portion of the capital would have been (C) be generated if a portion of the capital were (D) be generated if a portion of the capital was (E) be generated if a portion of the capital had been
key：（C）
if 条件从句的例题： 37. While some academicians believe that business ethics should be integrated into every business course, others say that students will take ethics seriously only if it would be taught as a separately required course.
(A)only if it would be taught as a separately required course
(B)only if it is taught as a separate, required course
(C)if it is taught only as a course required separately
(D)if it was taught only as a separate and requiredcourse
(E)if it would only be taught as a required course,separately
虚拟语气有非常明显的时间退格现象，即：条件从句谓语时态较主句时间轴上有所后退 拿题一举例： that would be generated if a portion of the capital were invested in another form. 主句中would过去将来，从句一般过去，出现时间退格
同理，该句可以有下几种变形 1.that would have be generated if a portion of the capital had invested in another form. 2.that will be generated if a portion of the capital is invested in another form. 情况2就是第二题