| 释义 |
ap·ple·ton layer AHDˈapəltən-,-tᵊn-
基本英英近义反义
阿普顿层
Noun:
the highest region of the ionosphere from 90 to 600 miles up which contains the highest concentration of free electrons and is most useful for long-range radio transmission近义词 F regionF区F layer电离层 |