问几道英语语法的简单问题 麻烦告诉我为什么选这个答案 谢谢

第一句话是非谓语结构,主动的时候用现在分词,被动的话用过去分词,这里是这个小男孩主动跟着他妈妈咯.后面的话by hand是表示用手,就是说用手拉着他，带着他

第二题先翻译句子:我感到困惑的是他是怎样收集到那么多邮票的,所以B,C先排除,其次puzzle about表示苦思苦想,这里没有这个意思，他不过是困惑而已,犯不找苦思苦想,所以选A

1. The shy boy appeared in the classroom, _____ his mother, who was leading him _____hand.
A. 你可以把句子补全为：
The shy boy appeared in the classroom and he followed his mother, who was leading him by the hand.
这时你会看到and he followed his mother中的he 就是the shy boy, 为了避免重复，把后面的and he followed 变为非谓语following .
B. by the hand 是固定用法。
又如：The man hit Bob on the head.
Don't pull me by the collar.

1，
the shy boy 是主语 Follow这个动作是主动的
所以不能用followed
by the hand
特指the shy boy 的hand 所以用the

2，主语从句用What
这里是从句，不用about