Face to the Sunshine "Keep your face to the sunshine and you cannot see the shadows"is a popular saying.It encourages people to make the best of a situation，to see the"bright side"of things.It calls attention to the way sunflowers follow the sun during the day.People have known about this phenomenon（現(xiàn)象） for a long time.Recently scientists have discovered how this works.They now why sunflowers keep their"faces"to the sunshine.
   Sunflowers move and respond to their environment.These flowers actually face the sun as it rises in the east and follow it as it moves across the sky until it sets in the west.Just like people，these flowers depend on the daily rhythms（節(jié)奏） of the day and night.Both the sunflowers and human beings wake up in the morning，follow the sun all day and then rest at night.
   During the day，young sunflower plants track the sun from east to west.The green flower head turns towards the sun.At night，the young plants turn east，waiting for the sun to rise in the morning.Adult sunflowers don't move.Once the flower is open，it faces only east.Scientists have discovered that this movement and lack of movement has to do with uneven（不均勻的） growth in the plant stems.One side of the stem gets bigger during the day，and at night the other side gets bigger.Certain genes（基因） control this growth.They respond to the light and cause the flowers to turn to face the sun.
   Scientists have found that young sunflowers that follow the sun have more biomass（生物量）--that means that they get bigger.Adult plants facing the east get warmer.That in turn attracts more bees and other insects that will help pollinate（授粉） the plant.This means that the plant can produce seeds and has a better chance of reproducing.

（1）The material above is a news report，isn't it？

No，it isn't.

No，it isn't.

（2）What do sunflowers usually do during the day？

They face the sun.

They face the sun.

（3）Why do both sunflowers and human beings depend on the daily rhythms of the day and night？

Because they both move and respond to the environment.

Because they both move and respond to the environment.

（4）When do the young sunflower plants turn to face the east？

At night.

At night.

（5）According to scientists，what causes the movement and lack of movement of the sunflowers？

Uneven growth in the plant stems.

Uneven growth in the plant stems.

（6）Do you like to be young sunflowers or adult sunflowers？Give your reason（s）.

I like to be young sunflowers.Because I can always follow the sun to move，have more biomass and be easy to get bigger.

I like to be young sunflowers.Because I can always follow the sun to move，have more biomass and be easy to get bigger.