单选题The teacher propose that&

问题补充：

单选题TheteacherproposethatJack___mathsorphysicsinsteadofEnglishbecausehewasquickatnumbers.A.must studyB.could studyC.studiedD.study

答案：

D解析考查情态动词。propose引导的宾语从句，谓语动词应用should+动词原形，故