I found _____ convenient to shop online at home .

it’s 

that

it

that was

考查强调句。句意：我发现在家网购很方便。这里it指代后面的to shop online。其中的强调句式是：主语+find it +形容词+to do，意为主语发现做某事是...的，故选C。

Her         for writing was a desire for women to get  the right to higher education.

motivation

qualification

talent

technique

考查名词词义辨析。句意：她写作的动力源自为女性获得更高教育的权利。motivation动力；动机；qualification资格；talent才能，天赋；technique技巧。故a desire for women to get  the right to higher educatio是她写作的动力。故选A项。

If you don't understand something, you may resrarch, study, and talk to other people          you figure it out.

because

though

until

since

考查连词。句意：如果遇到不懂的东西，你可以搜索、研究，和别人交流直到弄明白。A. 因为； B. 尽管；C.until直到；D.since自从，因为。根据句意可知，until符合语境。故选C项。