We can learn from the first paragraph that parents and grandparents
A. used to give out their assets at death.
B. no longer pass on their wealth to their offspring.
C. don"t care how their money is spent at all.
D. would not give their offspring financial help.
According to the experiments conducted by Frank Keppler and his colleagues,
A. living plants produce a high rate of methane.
B. dead plants produce a high rate of methane.
C. methane mainly comes from burning biomass.
D. methane can only be produced hydroponically.
According to the first paragraph, Aerographite is
A. six times lighter than the last record-holder.
B. created by American researchers in Hamburg.
C. the lightest material in the world so far.
D. less than a quarter the weight of air.
From the last paragraph we can learn that
A. 500 million to 600 million metric tons methane are produced yearly.
B. the production of methane increased by 10% and 30%.
C. experts are cautious about lab and field experiments.
D. there is no definite answer to plant methane production at present.
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