说明：  强烈推荐：单片机 C 语言程序设计师试题(含答案)。看一遍你的 C 水平一定有所提高！同时也了解自己的水平！
(Strongly recommended: Single-chip C language programmers questions (with answers). Thorougly you will definitely improve the level of C! At the same time understand their own level!)