单项选择题

What is said about the over 100 aircraft incidents in the past 15 years

A．They may have been caused by the damage to radio systems.
B．They may have taken place during take-off and landing.
C．They were proved to have been caused by the passengers portable computers.
D．They were suspected to have resulted from electromagnetic interference.
<上一题 目录 下一题>
热门 试题

单项选择题
According to the passage, which of the following sentence is true
A．RTCA has ordered that all airlines ban portable electronic devices from being used during "critical" stages of flight.
B．Individual airlines have the right to decide whether or not to ban portable electronic devices during flight.
C．Almost all airlines enforce a total ban of portable electronic devices during flight.
D．Experts have recommended airlines to prohibit passengers from using electronic devices during take-off and landing.
单项选择题
It can be inferred from the passage that the author______.
A．is in favor of prohibiting passengers use of electronic devices completely
B．has overestimated the danger of electromagnetic interference
C．hash' t formed his own opinion on this problem
D．regards it as unreasonable to exercise a total ban during flight
相关试题