单选题 If we ______ the oil company to build this paper mill, we ______ water pollution now.
A. had not allowed, would not have C. didn't allow, would not have
B. had not allowed, would not have had D. didn't allow, would not have had

【正确答案】 A

【答案解析】如果当初我们不同意石油公司建这个造纸厂，现在就不会有水污染的问题了。考查虚拟语气。本句是交错时态句。前半句是对过去事实的虚拟假设，需用过去完成时。后半句是对现在事实的虚拟假设，需用would do结构，故本题选A。