Anna Du was walking along the beach when she noticed plastics there.She reached down to pick them up，and quickly realized there were many more tiny pieces than she could deal with.It seemed impossible to clean them all up.
Du，12 years old at the time，tried to solve the problem like any good scientist—first，by doing a little research.That's how she learned that 8 million tons of plastics end up in the oceans every year.
Then she got to work building something that could help solve the problem：a remote-operated vehicle （遙控潛水器），or ROV.Her ROV can move through water and find plastics on the ocean floor.
The actually cool part of Du's ROV is the detection （探測） system.She uses a camera along with three different kinds of light to find the plastics.She also uses visible （可見的） light to find unnatural colors that might make the plastics stand out.
"She has a very good engineering sense to break down a problem like this and then go after it，" says engineer Casey Machado. "It sounds simple，but it's a level of thinking that's really amazing."
Du started attending public events and workshops at a university when she was five years old，and so she picked up the engineering skills necessary to build her ROV.She says actually getting her ROV to move through water well was not easy.She failed many times，but she never gave up trying and testing.
When asked about future plans，she mentions wanting to address the effects of climate （氣候） change. "I think there are a lot of problems that could be solved with new inventions，" says Du.
Du thanks her parents，who for years have taken her to student outreach activities，for supporting her interest in science，technology，engineering and math （STEM）.She says she has been able to meet students and scientists there.
"I know I want to be an engineer because I like building things to help solve world problems，" says Du. "But I'm not sure what kind of engineer I want to be yet."
（1）What did Anna Du notice while walking along the beach？
She noticed plastics.
She noticed plastics.
（2）What made Du succeed in building her ROV？
Her good engineering sense to break down a problem，the engineering skills necessary to build it，her not giving up and her parents' support.
Her good engineering sense to break down a problem，the engineering skills necessary to build it，her not giving up and her parents' support.
（3）Do you want to build something new to help solve world problems？Why or why not？
Yes，I do.Because the pollution is getting more and more serious now，I want to build something new to reduce pollution and make people's life better.
Yes，I do.Because the pollution is getting more and more serious now，I want to build something new to reduce pollution and make people's life better.
