50. In some countries, the governments
control the installment plan to .
A.
increase employment
B.
avoid depressions
C.
ensure that businesses make good profits
D.
ensure that people can pay for what they buy
C
A single night of taking the drug Ecstasy(摇头丸) can cause serious brain damage and speed up the start of Parkinson's
disease, scientists say. Just two to three Ecstasy tablets -- a quantity that
thousands of clubbers take during parties -- can permanently destroy brain
cells that affect movement and reasoning, according to American research that
links the drug to Parkinson's for the first time.
A study by a team at Johns Hopkins University in Baltimore, Maryland,
involving squirrel monkeys and baboons(狒狒) found that both species suffered
permanent damage to key cells called dopamine neurons, which are lost in
Parkinson's, after receiving three low doses of Ecstasy at three-hour periods.
The study is particularly significant because baboons are one of the
best animal models for the human brain. George Ricaurte, who led the research,
said that widespread abuse of the drug may already be claiming victims of such
neurological(神经性的) damage. “The most troubling
result is that young adults using Ecstasy may be increasing their risk for
developing Parkinsonism as they get older.”
Alan Leshner, a former director of the US National Institute on Drug
Abuse, said: “This study emphasizes the multi-aspect damage that Ecstasy can do
to users. We've long known that repeated use damages brain cells. This study
shows that even very occasional use can have long-lasting effects on many
different brain systems. It sends an important message to young people: don't
experiment with your own brain.”
Janet Betts, the Essex mother whose
daughter Leah died after a single Ecstasy tablet in 1995, said: “This
comes as no surprise. People can't see the effects at first, and they’re in
permanent denial(否认), saying it's not going to happen
to them. But we'll see the symptoms later, just as we have with smoking.”