题目

Now satellites are helping to forecast the weather.They are in space，and they can reach any part of the world.The satellites take pictures of the atmosphere (大气)， because this is where the weather forms.They send these pictures to the weather stations.So meteorologists (气象学家) can see the weather of any part of the world.From the pictures，the scientists can often say how the weather will change.Today，nearly five hundred weather stations in sixty countries receive satellite pictures.When they receive new pictures， the meteorologists compare them with earlier ones.Perhaps th有两种粒子，它们的质子数、核外电子数、粒子所带的电荷数均分别相等，这两种粒子      [     ]A、一定是同种物质的粒子 B、一定是不同种物质的粒子 C、不一定是同种物质的粒子 D、不一定是不同种物质的粒子