第22题选B,因为定语从句中的谓语动词forget为及物动词,缺宾语,故选关系代词that,它在此用作动词forget的宾语.
第23题选B,因为定语从句中的谓语部分 was founded为被动语态,它无需再用宾语,故不能选关系代词that,而应选关系副词when,它在此表示时间.
请再比较类似句子：
This is the factory where I want to work.这就是我想工作的工厂.(work为不及物动词where在从句中用作状语)
This is the factory that I want to visit.这就是我想参观的工厂.(visit为及物动词,that用作visit的宾语)
The reason why he can't come is that he is ill.他没来的是因为他病了.(come为不及物动词,why在定语从句中用作状语)
The reason that he put forth is very important.他提出的理由很重要.(put forth为及物动词,that在定语从句中用作其宾语)