Don’t call him at this time tomorrow, because he ________ a meeting with his teachers.

A．is having

B．is going to have

C．will be having

D．has been having

旅游经济结构优化的标志（）

A.资源配置的有效性

B.产业结构的协调性

C.生态环境的融合性

D.产业布局的地域性