词汇运用。用括号内所给的单词适当形式填空。 seriousinterest primarynecessary both . _____his parents are doctors. 2.My sister is a teacher. He works in a _____school. 3. Basketball and music are his two _____. 4. The girl is very _____about her work. 5. I think it's _____ for us to learn English well.