搜题请搜索小程序“爱下问搜题”
问题 单项选择题 A1型题

四氯化碳在细胞色素P450催化下还原脱卤形成三氯甲烷自由基·CCl_3可攻击生物膜引起（）

A.脂质过氧化

B.转录调节障碍

C.减少酶的合成

D.破坏酶的结构

E.细胞周期紊乱

答案

参考答案：A

单项选择题

Car crashes are the leading cause of injury and death among U.S. children, and though most of us now think of car seats as standard baby equipment, about half of all children under the age of four who died in vehicle accidents last year were not restrained. It is calculated that only about two-thirds of children ages five to fifteen buckle their seat belts.
Moreover, the traffic-safety agency estimates that even among parents who always strap their children in, 85% are not doing it properly. They often don’t know where best to place the kids, don’t use the proper restraint for their age and weight, or don’t install the safety seats properly. Despite the reports about front seats collapsing onto back seats when certain car models get in accidents, the safest place in the car for any child up to the age of 12 is still the back seat. Babies up to 9 kg and one year old should ride in rear-facing infant seats.
Never place a child under age 12 in the front seat with a working passenger-side air bag. These devices are discharged at 320 km/h and can be triggered by low-speed fender benders. They have killed 77 kids in the U.S. since 1993. If you must place a child in front, make sure the passenger-side bag is switched off.
Children over age one should ride in forward-facing safety seats with a five-point harness system. A child who weighs at least 18 kg or at least 1m high can graduate to a booster seat that elevates her so that the standard shoulder and lap belt fits properly.

Which of the following is NOT among the "improper ways" mentioned in the passage

A．They don’t know where best to place the child.

B．They don’t have the safety equipment for the child.

C．They don’t use the proper restraint for the kid’s age and weight.

D．They don’t install the safety seats properly.
查看答案
填空题

过流保护的动作电流按躲过（）电流来整定。
查看答案