您要查找的是不是：
- 中纬度时现E层 midlatitude sporedic E layer
- 在中纬度中和时现E层分子和金属离子的相对浓度 Relative concentrations of molecular and metallic ions in midlatitude intermediate and sporadic-E layers
- 时现E层 sporadic E layer
- 极光时现E层 auroral sporadic E layer
- 中纬度时现Ｅ层 mid-latitude sporadic E layer
- 赤道时现E层 equatorial sporadic E layer
- 几时 what time; when
- 薄层 folium
- 报时 give the correct time
- 折现 realization
- 中间层 mesosphere
- 必要时 in a pinch
- 面层 surface
- 折现率 discount rate
- 时有 occasionally; from time to time
- 图层 layer
- 半时 half
- 这块殖民地现已获得独立。 The colony has now attained nationality.
- 膜层 retia
- 1939年战争爆发时，她的父母在国外，他们直到战争结束时才能返家。 Her parents were abroad when the balloon went up in1939 and they could not return home until the war was over.
