1.这个以that引导的从句是宾语从句.
2.宾语从句有三种：
1）及物动词之后的宾语从句.
如：I know that you are busy.
2）介词之后的宾语从句.
如：I want to talk about what I have done today.
3）形容词之后的宾语从句.
如：I am sure that I'll win.
3.此从句即为上述第三种情况,所以形容词glad之后的宾语从句.