问题
选择题
Only after the woman had her own child ________ how difficult it was to be a mother.
A．she realized
B．had she realized
C．she had realized
D．did she realize
答案
D
题目分析：句意：只有当一个女人有了自己的孩子以后，她才认识到做一个妈妈有多难。Only位于所修饰的从句之前，并放在句首时主句要倒装，而且前面是过去时，所以后面要加助动词did，故选D。
考点：