Ludwick Marishane，a South African，was with his friends in Limpopo when they started talking about inventing something to put on your skin（皮肤）so you don't have to take a bath.Ludwick thought that this was a great idea.He did some research on the Internet，and he found some surprising facts.

    About 2，500，000，000 people around the world haven't got clean water.This is a huge problem because dirty water can create illnesses.One of them' is trachoma：8，000，000 people all over the world get trachoma every year.They wash their faces with dirty water，get ill and go blind.To stop trachoma，people don't have to receive expensive medical care.They have to wash their faces with clean water.That's it.

    Ludwick started thinking.He wanted to make something to help people in parts of the world where it's difficult to find clean water.He did more research on the Internet，and he did more thinking.Ludwick had a plan.He wanted to make a gel（凝胶）for people to put on their skin so.they don't have to take a bath.When he was at university，he never stopped thinking about his invention.He started to talk to other people about it，and three years later the dream came true.He made the gel and called it "DryBath".

    Ludwick is the winner of lots of prizes.People call him "one of the brightest young men in the world".He is happy about his success.DryBath is helping people to be healthy.And DryBath also helps to save water.That's important in many parts of the world，where it 's difficult to find clean water.Now he wants to invent other things and also wants to help other young people to become inventors.

（1）Trachoma is a kind of illness that may make people 　 　.

A.feel hungry

B.feel thirsty

C.become blind

D.become sleepy

（2）Ludwick invented the gel "DryBath" to 　 　.

A.treat people with skin trouble

B.make dirty water become clean

C.show people how to be an inventor

D.help people without enough clean water

（3）Which word best describes Ludwick according to the passage？ 　 　

A.Creative.

B.Brave.

C.Honest.

D.Humorous.

（4）What can we learn from Ludwick's experience？ 　 　

A.Luck is very important in achieving success.

B.People can succeed by sticking to their dreams.

C.Young people can easily come up with new ideas.

D.Going to university can make young people smarter.