问题
选择题
— I didn't tell my parents the secret yesterday.
— But you _____. [ ]
A. ought to do
B. ought to
C. should
D. ought to have
答案
答案：D
搜题请搜索小程序“爱下问搜题”
— I didn't tell my parents the secret yesterday.
— But you _____. [ ]
A. ought to do
B. ought to
C. should
D. ought to have
答案：D
CaCO3 
2MgO+C 
CH3OH(g)。某研究小组将2 mol 