Cambrdige - Lesson 12

Humans have binocular vision. That means that both eyes work together. They are placed at the front of our heads and we are good at telling how far away something is and how fast it is moving. ____________________. We no longer hunt in the same way but we use our vision to help us in many different ways in our daily lives.

• This vision helps humans hunt every day.

• In the past, our vision helped us to hunt in order to survive.

With your eyes you can see an object as small as 0.1 mm across. _____________. It seems impossible, doesn’t it? Our eyes are important and they need protection from damage and injury.

• You can tell the difference between 10 million different shades of colour.

• You can also see large objects.

Your eyelids and eyelashes protect your eyes. Eyelids can partly close and act as a sunshade in bright light. They can shut out light completely when you sleep. _______________. Your eyelashes trap dust that flies into your eye.

• They can close automatically if something is flying towards your eye.

• If you shine a flashlight in your eyes, it will hurt.

Tears wash your eyes. There are tear glands inside the upper eyelid. Tears form all the time in your eyes. ________________. It’s quite wonderful that our eyes can protect themselves, isn’t it?

• Blinking spreads the tears across your eye to help keep them clean and comfortable.

• Sometimes people cry when they are sad.

This spring, our teacher suggested we should get involved in a green project and plant some trees around the school. Everyone thought it was a great idea, so we started looking online for the best trees to buy. _____________________.

• That could mean the tree had a

  disease.

• But we soon found that choosing trees was quite

  complicated.

• It can be quite good for young trees, though.

f we wanted them to grow properly, they had to be the right type – but there were so many different ones available! So our teacher suggested that we should look for trees that grew naturally in our part of the world. _________________________.

• We knew they’d get as much pleasure from them as we had.

• But at least we were doing it in the right season.

• That way, the trees would be used to local conditions.

Then we had to think about the best place for planting the trees. We learnt that trees are happiest where they have room to grow, with plenty of space for their branches. The trees might get damaged close to the school playgrounds, for example. ________________________.

• So we tried to avoid areas where students were very active.

• However, our parents did offer to help with the digging!

• That could mean the tree had a disease.

Once we’d planted the trees, we knew we had to look after them carefully. We all took turns to check the leaves regularly and make sure they had no strange spots or marks on them. _________________.

• But we soon found that choosing trees was quite complicated.

• That could mean the tree had a disease.

• We knew they’d get as much pleasure from them as we had.

We all knew that we wouldn’t be at the school anymore by the time the trees grew tall, and that was a bit sad. But we’d planted the trees to benefit not only the environment, but also future students at the school. _______.

• We knew they’d get as much pleasure from them as we had.

• But at least we were doing it in the right season.

• So we tried to avoid areas where students were very active.