单选题It sounds like a science fiction, but researchers say it's a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too. The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte- literally, "fish killer. " It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding. Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish's nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them. Whether humans are affected by the dinoflagellate's toxin remains to be seen. Researchers think it's unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation. To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack.

单选题What do you think "hatching and rearing their young" means?

单选题The annual ______ of the department store starts tomorrow.

单选题In 1982, Hitachi was indicted for stealing confidential documents from IBM. As part of a court settlement, the company paid IBM hundreds of millions of dollars.

单选题The Polynesians who colonized Hawaii sometime between A.D. 500 and A.D. 1,000 found use for many indigenous plants.

单选题Now I don't want to {{U}}intrude{{/U}} because John's house is full of visitors.

单选题The earliest form of artificial lighting was fire, which also provided warm and protection. A. hot B. sunshine C. warmth D. safe

单选题Teenagers in the 1950s, who had to ______ an increasingly atomized family life and domestic and international tensions, scorned the sterile version of American life.

单选题The big retailers are starting to think small, too. Sainsbury's and Tesco have launched convenience-store chains, called Local and Express, respectively—that have fast become ______ in British towns.

单选题Careful testing is {{U}}necessary{{/U}} before any more experiments can continue with the exploring submarine.

单选题His ______ behavior made everyone nervous. He was always rushing to open doors and perform other small tasks, apologizing unnecessarily for any inconvenience that he might have caused. A．oblivious B．observant C．obsequious D．obsolescent

单选题There was no enmity between us, so we were able to reach an agreement on the sale of the property.

单选题Some of these online services are free, while others ______ a charge.

单选题Our holiday {{U}}is doomed{{/U}} to failure without you.

单选题An educational theorist, Paul Woodring probably summed up James's significance to education most succinctly. A. concisely B. broadly C. precautiously D. conclusively

单选题The environmental balance among ecological communities is exceedingly complex.

单选题The food was divided ______ according to the age and size of the child. A. equally B. individually C. sufficiently D. proportionally

单选题All the staff members of the department made zealous efforts to clean up the hall for the Christmas party. A. enthusiastic B. concerted C. gigantic D. dedicated

单选题In addition to cultural differences, overseas students have to overcome linguistic ______ as soon as possible.

单选题That MGM Grand Youth Center is open to children 3-12 years old ______ what hotel they are staying in. A. regardless in B. regardless of C. regardless on D. regardless from