有一群鸡和兔，腿的总数比头的总数的2倍多18只，兔有几只？
根据题意可得，
兔子的只数是：18÷（4-2）=9（只）．
答：兔有9只．
—It was surprising that your brother should have________my sister the moment he saw her yesterday.
—Yes, especially since it had been 30 years since they last saw each other. [ ]
A. picked out
B. figured out
C. turned out
D. worked out
PPC接车软件收不到三型机任何数据（包括自检和复位信息），可能与下面哪种故障有关（）。
A.主控连接电缆松动
B.端口设置错误
C.CPU板故障
D.通讯板故障
E.串口电缆故障
