单项选择 -Where's Mike? -He is working ( ) physics ( ) in the classroom. A.in；problem

分类: 作业答案 • 2021-12-18 12:00:16

问题描述：

单项选择 -Where's Mike? -He is working ( ) physics ( ) in the classroom. A.in；problem
B.out；problem
C.in；problems
D.on；problems

答

D.on；problems
work on从事,演算