下列现象中，说明分子在不停地做无规则运动的是（     ）

   Maria lives in the beautiful countryside．She usually gets up early in the morning，1she's never late for schoo1．After getting up，she often showers and has a good breakfast．Then she2 for school at around 6：303her home is very far from schoolshe likes riding her bike better than4the bus．It takes her about an hour5her bike．It's so long! On the way，she sings and sings so she always feels6．Also she thinks that it's good for her health7to school by bike．
   After school she usually goes back8with her friend，Linda．Linda’s home is nearer than Maria's． It's only three miles from her home9schoo1．Linda likes riding，too．And she also thinks that it is a good10of transportation．

如图所示的电路中，三个灯泡L₁、L₂、L₃的电阻关系为R₁＜R₂＜R₃，电感L的电阻可忽略，D为理想二极管．电键K从闭合状态突然断开时，下列判断正确的是（   ）

我国最大的邻国是（　　）