The most significant limitation of VHF signals is that they _______ ．

单选题

The most significant source of man-made radiation exposure to the average person is from_____.

答案解析

单选题

The most significant limitation of VHF signals is that they _______ ．

答案解析

单选题

Perhaps the most significant postwar trend was the decentralization of cities throughout the UnitedStates，( )when massive highway-building programs permitted greater suburban growth.

答案解析

单选题

Hawass said the collection of workers’ tombs, some of ______ were found in the 1990s, were among the most significant findings in the 20th and 21st centuries.

答案解析

单选题

Equipment without significant effect on the weight or balance of the airplane need not be listed.

答案解析