He began to take political science ________ only when he left school. 

Food safety is ________ important, so the government spares no efforts to prevent food pollution.

____ the search engine just gave me some brief introductions rather than the whole content of the book to read.

“John” and“Tom” are _______ names in the English-speaking countries.

— I did really well in the examination, Li Ke.—I did ______. I got full mark.