我们周围有些声音之所以称其为噪音，主要是因为[ ]

A．声音太刺耳

B．音调太高

C．妨碍人们正常的工作、学习和休息

D．不是乐器发出的

Several of the passengers were hurt and one was taken to hospital. Luckily _____ was killed. [ ]

A. no one

B. not all

C. none

D. no other