Question

Students are supposed ________ hard at school.

1. A.
   studying
2. B.
   studied
3. C.
   to study
4. D.
   study

Answer 1

C
试题分析：考查短语be supposed to do sth 应该做某事，被期望做某事。句意：学生们应该在校努力学习。选C。
考点：固定短语be supposed to
点评：be supposed to do sth 应该做某事，被期望做某事。本句式中to是不定式符号，不能接动名词或者名词，只能接动词原形。