Theyre global, theyre everywhere, and they didnt get to be completely global if they werent very skilled at being masters of adaptation, he says. 老师好，这段抄自一篇有关老鼠的的文章。我感觉从这段话从 and 之后就是虚拟语气，可是，在if后面用了were之后，主句也没用相应的 would do，而是用了 did 。我有点不太了解～
关于虚拟条件句if从句和主句谓语动词形式，《剑桥语法》有明确说明。
Huddleston著 The Combride Grammar of the English Language （剑桥语法）第751页
14.2.2 The form of remote conditionals
Tense and mood restrictions
The verb of the protasis (条件从句）must be the irrealis form were or a preterite (过去时）with the modal remoteness meaning. The verb of the apodosis（结论主句） must be a modal auxiliary; this too must be a modally remote preterite, except where the modal has only a present tense form.
用传统语法术语将这段话翻译如下：
14.2.2 虚拟条件句的形式
时态和语气的限制
条件从句的动词需要是虚拟语气形式were, 或者表示非真实意义的过去时。主句的动词需要是个情态动词；这个情态动词也需要是表示非真实意义的过去时，除非该情态动词只有目前时态形式。
由此可知，虚拟条件句的主句需要含有情态动词的过去形式，除非某个情态动词没过去形式，而用目前形式。
网友的句子中，and后显然是与事实相反的假设，主句是由此所做的推论。主句没用情态动词过去式是语法错误。didnt get...应改为 wouldnt have got...。
