两个或多个动名词短语并列作主语的时候 谓语动词是单数还是复数形式

两个或多个动名词短语并列作主语的时候 谓语动词是单数还是复数形式?这要看叙述的是一件事还是两件以上,如果是一件事,谓语动词是单数,如果是两件事,谓语动词是复数形式.
如：Going to bed early and getting up early is a good habit.
Watching TV and reading books are really interesting.