15.
I am a dragon hunter.Dragonflies,that is!My name is Keith Wilson.I'm an odonatologist.That's a scientist who studies dragonflies.I don't hunt to kill.I hunt to discover.So far,I have helped to find many new species,or kinds,of dragonflies.
Flying Colors
dragonfly
Why do I look for dragonflies?The answer is simple.I love them!They can speed by.They can make sharp turns
and sudden stops.They can even fly backward.
Best of all,dragonflies are beautiful.They come in many colors and patterns.Who doesn't like looking at these amazing insects?
Super Sizes
Dragonflies come in many sizes.The smallest one is the size of your thumbnail.The largest one would cover your face.I recently looked for the heaviest dragonfly in the world-the giant petaltail.It lives in Australia.
Built to Hunt
Dragonflies are built to hunt.They have two compound(復(fù)合的) eyes.Each eye is made of 30,000smaller eyes.All those eyes help a dragonfly see everything.A dragonfly can spot a tasty meal from up to 18feet away.
Dragonflies have six legs.The insect cannot walk on its legs,however.It uses its four wings to get around.It can fly up to thirty miles per hour,looking for food.
From Water to Air
A dragonfly begins its life underwater.It hatches (孵化)from an egg and becomes a larva.A larva is a young dragonfly.It can swim,but it cannot fly.
A larva lives in a lake or stream.It can grow for several years.Then it crawls out of the water.It sheds(脫落) its hard skin and becomes an adult.
An adult dragonfly doesn't have much flying time.Some adults live for only a few weeks.Others are around for several months.During that time,a dragonfly is very busy.It flies.It hunts.It eats.If the dragonfly is female,it also lays eggs.Soon there will be more young dragonflies.
Dragonflies in Danger
I worry about dragonflies.People are cutting down forests where the insects live.That could cause some species to die out.I want to protect these tiny dragons for others to see and enjoy.
53.The dragonflies are built to hunt because theyD.
A.have six legs
B.walk on their legs
C.begin life underwater
D.have compound eyes
54.After reading this passage,what can we conclude about dragonflies?B
A.Dragonflies are easy to find.
B.Some dragonflies are in danger.
C.Dragonflies look like small dragons.
D.Some dragonflies can be harmful.
55.By writing the passage,the writer wants to tell usC.
A.how to photograph dragonflies
B.how to protect dragonflies
C.the life of dragonflies
D.the living habits of dragonflies.