Should we be afraid of sharks？Maybe not.Some scientists do some research about the causes of shark attacks（袭击） and say that sharks don't like the taste of humans!In fact，most people who were attacked didn't die.They usually received only one bite（咬伤）.Why is this？
   There are many explanations（解释） of why sharks sometimes attack people.One is that sharks are just curious（好奇的）.
   We know that sharks are the strongest animals in their environment，so they are not afraid of anything.It means they are curious when they see something that it isn't usual.Because they don't have hands or feet，the only way they can learn about an object is to bite jye.ai.It is thought that sharks sometimes bite humans for this reason，and then swim away.
   Scientists also say that sharks don't want to waste energy trying to eat a human，because we have a lot of bones（骨头）.It is hard for a shark to eat us because sharks don't have hands，and they can't pull the meat off our bones.Maybe that's why they only bite us once.
   Another guess is that sharks attack humans by mistake.Some sharks，such as the great white sharks，may sometimes mistake humans for a seal（海豹）.People lying on the sea look like seals when seen from below.Sharks like seals because they are fat and delicious.
   No matter why shark attacks on humans，sharks should be afraid of us.Sadly，we kill almost 40 million of them each year.

（1）How do sharks find out about an unusual object according to the passage？

A

A

A．By biting.
B．By smelling.
C．By touching.
（2）According to the passage，what might sharks think of humans？

C

C

A．Friendly.
B．Responsible.
C．Not delicious.
（3）Why does the writer say sharks should be afraid of humans？

B

B

A．Because humans have hands and feet.
B．Because many sharks are killed by humans.
C．Because there are more humans than sharks in the world.
（4）What would the writer write the passage mainly for？

C

C

A．To tell surfers to stay away from sharks.
B．To ask people to stop killing sharks.
C．To let us know the reasons for shark attacks on people.