More and more people know the importance of protecting the environment.

问题描述:

More and more people know the importance of protecting the environment.
这里的importance用不用加s?
还有一个别的问题:
花费太多的时间看电视会妨碍学习.
_______too much time on TV can _____in______ _______ _______ schoolwork.
第一个空填spend还是spending?

importance是不可数名词,不加s

填Spending,动名词做主语