关于非限制性定语从句中的先行词which，请看下面我写的两个句子是不是有问题？
Nowadays, an increasing number of people arelearning online, which has both advantages and disadvantages.
这个句子想表达在在线学习这件事有好有坏（而不是愈加多的人使用这种方法有好有坏），那样which指代的就不是前面的句子了，而是are learningonline这个谓语动词的词组了。
It's important to clean our teeth everyday, whichcan help us keep healthy.
这个句子想用后面的定语从句表达天天刷牙可以帮助大家维持健康，但细究的话which就指代前一句的to do 不定式了。
正常学的定语从句的which，要么指代名词，要么指代前面整个句子，像这两个例句如此是否有问题？期望有老师能给与指导。
很感谢！
大家看一下夸克的例句：
They say he plays truant, which he doesn't. [l]
He walks for an hour each morning, which would bore me. [2]
以上两个句子中，which的先行词无疑不包含句子的主语，而只不过黑体部分, 即先行词为谓语动词+宾语或状语，即谓语部分。二个句子区别在于，第一句中的which表面上看等于play truant, 实质是doesn't后省略了do，which意为it。而第二句则which直接等于it，it指代walking for an hour each morning.
Things then improved, which surprises me. [3]
Colin married my sister and I married his brother, which makes Colin an! me double in-laws. [4]
以上二个句子中，which的先行词为前面整个主句的内容。
大家再看剑桥英语语法的例句：
He told me to design it myself, which I simply can't.
They advised me to call the police , which I did immediately.
这二个例句显然which的先行词为主句中的动词不定式。
改为并列句结构，则上述二句分别为：
He told me to design it myself, but I simply can't do it.
They advised me to call the police, and I did it immediately.
以上二句删去并列连词，用which替换it，就得到这种句子关系分句。
所以，which引导非限制性定语从句，其先行词既能够是前面整个主句的内容，也可以是主句的谓语动词，与非谓语动词部分。夸克把这种which从句称为句子关系分句sentential relative clause，剑桥英语语法把这种which分句称为补充语分句supplementary clause
