glad to do 还是doing呢

是be glad to do sth，而不接动名词doing。

固定搭配be glad to do sth，意为乐意做某事，很高兴做某事。

如：I am glad to read books. 我乐意读书。这里的to 是动词不定式的标志，而不是做介词使用，所以也就不沿用英语中介词后面+动词ing形式的惯例，所以是be glad to do sth。

be glad / happy/pleased to do sth，三个词意思一样。

1、某人高兴做某事。

I' m glad to hear from you.

2、我很高兴收到你的来信。

They were happy to meet again each other.

3、他们彼此再次相聚都很高兴。

it was pleased for me to pass the exam.

对于我来说考试过了我很高兴