问题
多项选择题
局麻药的快速耐药性与下列因素有关，但除外()
A．局麻药的浓度
B．追加时机
C．神经的粗细
D．局麻药的pKa
E．反复注药次数
答案
参考答案：A, C
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局麻药的快速耐药性与下列因素有关，但除外()
A．局麻药的浓度
B．追加时机
C．神经的粗细
D．局麻药的pKa
E．反复注药次数
参考答案：A, C
Part A
Text 1
| To try to bring context back, Hueter and Burgess teamed with NOAA and Sea Grant to hold a press conference in the spring of 2002 at the National Press Club. "We wanted to try to get the press to adopt some rules of engagement," Hueter says. "We wanted them to calm hysteria, use perspective and write more articles not focusing on attack." Burgess and Hueter stress sharks’ importance in the ecological balance and health of the oceans, which depend on complex food webs involving every sea creature. Just like apex land predators, sharks are important in that balance. "They’re a top predator and few in number," Hunter says. "When they’re eliminated, there’s nothing to fill in that place." More than 100 million sharks are killed each year by fishermen, which can devastate certain species that grow slowly and can take as long as 15 to 20 years to reach reproductive age. The prehistoric creatures continue to fascinate scientists with their immune and reproductive systems and their advanced senses and they’ve been used as a classic vertebrate anatomy tool for years because they bear many similarities to humans. Scientists believe that unprovoked attacks are cases of mistaken identity, or the sharks just having a taste to see whether they want some more. Most of attacks are not fatal. According to the International Shark Attack File, globally, there were 55 unprovoked attacks in 2003, with four fatalities. In the US, one is 30 times more likely to be struck by lightning than to be attacked by a shark, and bees, wasps and snakes cause more deaths each year than sharks. The number of attacks seems to have risen dramatically in the 1990s, but this is partly attributed to more thorough record-keeping by the International Shark Attack File and more public awareness leading to more reports. Also, the number of shark-human contacts in a year is directly proportional to the number of humans in the sea. As the world population increases and more and more people, take to the waters, it is logical that shark attacks, along with other water-related injuries, will increase. Due to overfishing, shark populations are seriously declining in some cases and holding at reduced numbers in others. According to George Gerbner’s Cultivation Theory, people can be affected by the amount and the content of the TV and movies they watch. The portrayals of things in these media can create a false sense of society. For example, one who watches a lot of crime shows could perceive the world to be a much more dangerous place than it actually is. So be it with TV shows and movies that feature shark attacks. Things can appear to be more common than they actually are. But this isn’t the only reason people fear sharks--sharks do have teeth and can bite. Humans could see other predators coming and kill them with a single shot, but in shark territory, the predator is invisible. |
Why are sharks important in the ecological balance and health of the oceans
A．They are apex carnivores and reduced in numbers.
B．They are killed and few in numbers.
C．They are certain species that grow slowly.
D．They are flesh-eating animals and kill other sea creatures.