1. radiation Experts know that portable devices emit radiation, which affects those wavelengths which aircraft use for navigation and communication.(1999.6)【全真测试】A. 阳光 B. 放射线 C. 激光【译 文】专家了解到这种可便携的装置会辐射射线,这种射线会影响飞行器用来导航和和联络的波长。【四级词义】n. 放射线,放射物,辐射【猜 一 猜】 radical radiance radiant【Key】 adj. 放射的,辐射的 n. 发光,光辉 adj. 发热的2. racialThe racial discrimination issue was a political hot potato in the United States in the past.【全真测试】A. 种族的 B. 饮食的 C. 卫生的【译 文】