—Hi, Lily. Don’t forget to watch I’m a Singer at 10:00 this Friday night!

—What a pity! I       in a plane to Hainan for a meeting then.

A．will sit

B．will be sitting

C．am sitting

D．sit

下列哪些不是二氧化碳对呼吸的调节途径（）

A.直接刺激呼吸中枢

B.刺激颈动脉体和主动脉体

C.加强牵张反射

D.刺激延髓化学敏感区

E.刺激外周呼吸肌