Do you know why different animals or pests(害虫)have different colors? The colors are mainly used to protect themselves．

  Some birds like eating locusts(蝗虫)，but birds cannot easily catch them．Why? It is because locusts change their colors together with the change of the colors of the crops. When the crops are green，locusts look green．But as the harvest time comes，locus change to the same brown colors as the crops have．Some pests with different colors from the plants easily found and eaten by others．So they have to hide themselves，appearing only at night．

Some animals move quietly through forests．They cannot be easily seen by hunters(猎人)．This is because they have the colors much like the trees’．

    A kind of fish in the sea can send out a kind of black liquid(液体)when it faces danger．While the liquid spreads over，the fish’s enemies cannot find it．And it immediately swims away．So it has lived up to now though it is not strong at all．

1．From the passage we can learn that locusts________．

    A．are small animals                       B．are easily found by birds

    C．are dangerous for their enemies            D．can’t be easily caught by birds

2．How can pests with different colors from the plants keep out of danger?

    A．They run away quickly．

    B．They have the colors much like their enemies’．

    C．They hide themselves in the daytime and appear at night．

    D．They have to move quietly．

3．Some animals Can keep safe in the forest because________．

    A．they have the colors much like the trees’

    B．they move quietly

    C．they like brown and grey colors

    D．they live in the forest

4．Why can the kind offish in Paragraph4 live up to now(直到现在)?

    A．Because it is very large and strong．

    B．Because the liquid it sends out can help it escape when in danger．

    C．Because the liquid it sends out call kill its enemies．

    D．Because it swims very fast and Call escape very quickly．

5．Which is the best title for this passage?

    A．The Change of Colors．

    B．Colors of Different Animals and Pests．

    C．The Main Use of Colors with Animals and Pests．

    D．Some Animals and Pests．

A recent survey of 2000 parents in Britain showed that they are often afraid of science questions asked by their curious children only because they have no idea what the answer is. Here is a list of some simple questions that you can ask your parents to see if they know the answers.
Q: Why is the sky blue?
A: You probably know white sunlight is made up of seven colors. While it moves in a straight line when going through space, it starts to divide as it hits “raised area” in the atmosphere. The ones with longest wavelengths pass through easily. The blue , however , can be taken in by the gas molecules (分子) because it has a shorter wavelength , which in turn scatters (使分散) it in different directions. That’s why when you look up at the sky, it appears to be blue.
Q:Why does the moon sometimes appear during the daytime?
A: The simple answer to that is because just like any other object it is being lit by the sun. As long as it is around 45 degrees or even 90 degrees off the sun, it will receive light and be able to be seen. The only time it is not able to be seen during its 28-day orbit (轨道) around the earth is when it is right between the earth and the sun. That’s because its back , which is not lit by the sun, is facing us.
Q: Where do birds/ honeybees go in winter?
A: While the bird part is quite easy, since a lot of them get together and travel, the honeybee part is likely to puzzle your parents. It turns out that these busy insects stop being that active when the temperature drops below 50°F. Instead ,they get together in the lower central area of the hive （蜂巢）and form a ball around their queen. This helps keep both warm enough to survive the cold winter months.
【小题1】The sky looks blue mainly because the color blue in the sunlight_______.