If you are writing or studying, it makes much difference where the light comes from. People use         and pens every day. They have to be very careful about the way of the light because the light shines on their work.
Every         gets its light either from daylight         the window         from the lamps or electricity,         no matter what kind of light it is, the way it shines towards our books or work is very important to the eyes.
Take a book and sit with your         toward the window, and try to read. Your shadow(影子) falls all over the page and makes it         for your eyes as if you were in a         room.
Now turn around and face the window. The page is         shadow again, while the bright light is in your eyes.
Try sitting with your         side toward the window. This is very good for         , but if you were writing, the shadow         fall across the page and bother you         .
There is another way – sit         your left side to the window. Now everything is perfect for writing as well.
Whatever kind of light is in the room, the rule about the right way to sit is         the same.

A．eyes B．heads C．books D．hands

A．man B．woman C．house D．animals

A．from B．through C．into D．inside

A．and B．then C．as D．or

A．but B．until C．if D．when

A．side B．back C．body D．front

A．good B．bad C．useful D．clear

A．bright B．clean C．dirty D．dark

A．in B．into C．on D．to

A．front B．back C．left D．right

A．speaking B．reading C．writing D．studying

A．can B．may C．would D．will

A．few B．a few C．little D．a little

A．by B．with C．against D．near

A．only B．never C．not often D．always