如图用刻度尺A、B分别测量同一物体的长度，A尺示数是____cm，B尺示数是____cm．

如图所示，电路中R₁的阻值为6Ω，闭合开关S，电流表A₁的示数为1.2 A，电流表A₂的示数为0.3A，则R₂的阻值是（  ）

     Tom and Mike are good friends. They are good with children. They want to find jobs in summer vacation. This Friday Tom tells Mike that Sunson School Trip needs teachers to help with sports, music and computer. Mike is glad to know that.
    Tom can play basketball, volleyball, and he can swim. Mike can play the violin, the trumpet, the drums and the guitar, and he can swim,too. Tom and Mike like computers very much. Can they join Sunson School Trip?

空气中含量较高的气体是氮气和氧气，氮气和氧气在放电的条件下发生化学反应的微观模拟示意图如图所示：

请回答下列问题

下列属于我国塑料包装制品回收标志的是（   ）