按照世界卫生组织规定的牙位记录方法，26是

A．上颌左侧第一磨牙

B．下颌左侧第一恒磨牙

C．上颌左侧第一恒磨牙

D．下颌左侧第一恒磨牙

E．上颌右侧第一恒磨牙

（）around the Water Cube, we were then taken to see the Bird's Nest for the 2008 Olympic Games.

A. Having shown

B. To be shown

C. Having been shown

D. To show