Exploring ________ space is exciting, yet dangerous. There is _______need for both robots and humans for space exploration.

A．the; a

B．a; the

C．/; a

D．/; /

呼吸道感染（）

A.咳嗽伴发热

B.咳嗽伴胸痛

C.咳嗽伴呼吸困难

D.咳嗽伴咯血

E.咳嗽伴哮鸣音