案例分析题 The word "darted" in paragraph 5 can be best replaced by（）

A．Telephone was invented by a French engineer.
B．Roman soldiers sent the important message by spelling out the words.
C．African soldiers shouted from tower to tower to pass message.
D．Only by using telephone could people send speech sounds quickly.

A．it is true that life in America is much faster than that in any other city
B．people living outside big cities are lazy and miserable
C．most American people enjoy living in the suburbs of big cities
D．those who are busy are not necessarily unfriendly