【单选题】

There is something that our bodies must not have. We do not want to have illness or disease. When we are ill, we stay in beD、We can’t work and we can’t play. We feel ill and we are unhappy.

There is something that our bodies must not have. We do not want to have illness or disease. When we are iii, we stay in beD、We can’t work and we can’t play. We feel iii and we are unhappy.
One cause of illness and disease is dirt.Dirt causes illness. If we want to see how dirt causes disease, we need a microscope. When we look at some dirt through a microscope，we can see germs．Dirt is full of germs but they are too small to see without a microscope．They are very，very small but they are alive．They can go inside things．When germs go inside fruit，the fruit becomes baD、We can’t eat it．When germs get in side milk，the milk becomes sour．We cannot drink it． When germs get inside our bodies，we become ill．
Milk may get sour because ______.A．there is more water in it
B．there is sugar in it
C．there are germs in it