频率越高，空间路径损耗越（）。
The operation between two fuel injections is called a working cycle, which consists of a fixed sequence of eventsWhat does "which" mean in this sentence?（） a working cycle。 the operation。 two fuel injections。 event。
A line of position derived from a loran reading is a section of a(n) （）. straight line。 arc。 parabola。 hyperbola。
HLR存储器两类数据：一是（）、二是（）。
A light used to signal passing intentions must be an （）. all-round yellow light only。 all-round white light only。 all-round blue light only。 alternating red and yellow light。
The operation between two fuel injections is called a （）.
