判断伤员呼吸是否存在的方法是：看伤员的胸腹壁有无起伏动作；用耳贴近伤员口鼻处，听有无

Once a group of 17-year-old schoolboys decided to break the world basketball marathon（马拉松）record. They wanted to play for 90 hours ,breaking the record by adding 6 hours . Each team had 9 players, with 5 at a time. The boys decided each person would play 21.5 hours and then rest for 2 hours. Then they started at 6 o’clock in the evening.

The first night was very hard for the players. When it was their turn to rest, they were too excited to fall asleep at once. On the second night,they fell asleep as soon as they stopped.Some of them had trouble with their feet and hands, but the only serious problem was a psychological（心理学的）one. Each boy was thinking: Why am I doing this? How can I play any longer? After the third night, the players knew they could finish the 90 hours. The basketball on the fourth nigth was very slow. But in the final hours, the players got better. For the last few minutes, the players looked as fresh as when they started. How happy everyone was!

小题1:Before this basketball marathon, the world record was      .

A．84 hours

B．86 hours

C．90 hours

D．96 hours小题2:The first night was hard for the players because     .

A．they were too excited to sleep

B．they only slept for a short time

C．no one watched them play

D．it was very long小题3:The sentence“the players looked as fresh as when they started.”Here“fresh”means       .

A．不熟练的

B．兴奋不己的

C．精神饱满的

D．伤痕累累的小题4:Which of the following is Not true?

A．Some of the boys were hurt when they played

B．It was hard for the players to fall asleep for the first night

C．The boys started playing at 6 o’clock in the evening

D．In the end,all the boys felt happy

图中理想变压器原、副线圈的匝数之比为2：1，现在原线圈两端加上交变电压U=311sin(100πt)V时，灯泡L₁、L₂均正常发光，电压表和电流表可视为理想电表．则下列说法中正确的是

A．该交流电的频率为100Hz

B．若将变阻器的滑片P向上滑动，则电流表读数变大

C．电压表的示数为155.5V

D．若将变阻器的滑片P向上滑动，则L1将变暗、L2将变亮

药物在体内的相互作用体现在药动学方面的有哪些

阳离子型高分子混凝剂的混凝作用机理主要是（）。

A、压缩双电层

B、吸附电中和

C、吸附架桥

D、沉淀物的卷扫或网捕

信号干线电缆所设专用屏蔽地线，其接地极引线允许接至扼流变压器中心连接板。