说明：  at命令调试精灵 可以执行at命令，at命令被存放在队列里 提高了at命令执行的正确性，只有一个命令执行完毕后，才会执行下一条。
(at the command debug wizard can perform at the command, at the command are stored in the queue in order to improve the at the correctness of the implementation, there is only one command is finished before the next one.)