查耳酮的颜色通常为
A．无色B．灰黄色C．橙黄色D．红色E．蓝色
参考答案：C
In recent years travel companies have succeeded in selling us the idea that the further we go, ____ . [ ]
A. our holiday will be better
B. our holiday will be the better
C. the better our holiday will be
D. the better will our holiday
健康人的无氧阈一般约为最大摄氧量的（）.
A、40%～50%
B、50%～60%
C、60%～70%
D、70%～80%
E、80%～90%
