阅读理解。
We produce 500 billion of plastic bags in a year world-wide and they are thrown
away polluting oceans, killing wild-life and getting dumped in landfills where they take
up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a
solution.
The 16-year-old Canadian high school student, Daniel Burd, from
Waterloo Collegiate
Institute, has discovered a-way to make plastic bags degrade(降解)in as few as 3months,
a finding that won him first prize at the Canada-Wide Science Fair, a $10,000 prize, a
$20,000 scholarship, and a chance to revolutionize a major environmental issue.
Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by
microorganisms(微生物). If those microorganisms could be identified, we could put them
to work eating the plastic much faster than under normal conditions.
With this goal in mind, he ground plastic bags into a powder and concocted(调制)a
solution of household chemicals, yeast(酵母)and tap water to encourage microbes growth.
Then he added the plastic powder and let the microbes work their magic for 3 months. Finally,
he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead
bacteria as a control. Sure enough, the plastic exposed(暴露)to the live bacteria was 17%
lighter than the control after six weeks.
The inputs are cheap: maintaining the required temperature takes little energy because microbes
produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.
"Almost every week I have to do chores and when I open the closet door, I have piles of plastic
bags falling on top of me. One day, I got tired of it and I wanted to know what other people are
doing with these plastic bags. The answer: not much. So I decided to do something myself." said
Daniel Burd.
1．Daniel Burd won first prize at the Canada-Wide Science Fair because ____.
A．he found a new kind of microorganism
B．he contributed much to environmental protection
C．he found a way to degrade plastics in shorter time
D．he could encourage microbes growth in an easier way
2．Daniel Burd exposed one plastic sample to dead bacteria to
A．make the live bacteria work better
B．test how effective his method was
C．know which bacteria worked faster
D．control the temperature in the process
3．Maintaining the required temperature takes little energy because ____.
A．plastics can get hot easily
B．microbes can produce heat themselves
C．much carbon dioxide is produced
D．the temperature can be controlled
4．Daniel Burd got his idea from ____.
A．his school textbook
B．the failure of researchers
C．his everyday work
D．the practice of other people
