________his famous number 23 shirt, Michael Jordan became the most successful basketball player in the history of the game.

A．wearing

B．wears

C．worn

D．To wear

空气中氧浓度降低到( )以下，致使机体组织的供氧不足，就会引起头晕、恶心、调节功能紊乱等症状。

A．14%
B．15%
C．16%
D．17%