Do you know who( )math this term?1.teach they 2.teaches their 3.teach their 4.teaches them

题目

Do you know who( )math this term?1.teach they 2.teaches their 3.teach their 4.teaches them
请说明考点并翻译,

答案

答案：4.teaches them
考点：代词各种形式的具体用法和主谓一致.
翻译：你认为这学期谁会教他们数学呢?
解析：they为主格代词,在句中只作主语,不作宾表,表语,故1不对；their是形容词的物主代词,在句中作定语,后必须带一个名词,math作teach的直接宾语,故2不对；who来作主语时,如果没有上文限制或提示,一般当作第三人称单数来看待,谓语动词应用第三人称单数,故3不对.
另：teach sb.sth.教某人某物/某事