问题
选择题
The achievements of the greatest minds in science could never have been reached________ the patient work of hundreds of others．
A．were it not for
B．had it not been because
C．had it not been for
D．if it had not been
答案
答案：C
考查虚拟语气。If虚拟条件句，可省略if，而把were/should/had提到句首。根据could never have been可知，是对过去的虚拟，故条件句用过去完成时，把had提前，省略if。故选C。