单项选择题

A．Crowded air traffic.
B．The large size of airplanes.
C．Mistakes by air traffic controllers.
D．Bad weather.
<上一题 目录 下一题>
热门 试题

单项选择题
A．4,000 years ago.B．3,000 years ago.C．2,000 years ago.D．1,000 years ago.
A．4,000 years ago.
B．3,000 years ago.
C．2,000 years ago.
D．1,000 years ago.
单项选择题
A．For protection against other dogs.B．For protection against other animals.C．Just for fun.D．For the purpose of guarding the house.
A．For protection against other dogs.
B．For protection against other animals.
C．Just for fun.
D．For the purpose of guarding the house.
相关试题