前臂静脉团注增强扫描，肺动脉的循环时大约为（） A.10±秒 B.20±秒 C.30

阅读下面短文，并借助上下文和插图补充所缺信息。每个空只能填写一个意义相符、形式正确的单词。

     Li Ming is a middle school student. His 15th birthday is coming on  1  3rd. One day, Li Ming walked past

the shoe shop at the street corner. Once again, he stopped to look at the shop  2 . He felt happy to see the

shoes that he wanted very much were still there. He really wanted to have  3  for his birthday. Looking down

at his old shoes, he felt sorry for himself.

     He sadly walked away and thought  4  to tell his mother about it. He knew she would give him  5  he liked

if she could. But he also knew very well she had little money for that ￥1299-Nike Shoes. He  6  not to go

home at once, as he didn't want to upset his mother. So he went to the park and sat on the  7 . There he saw a

girl in a wheel chair. He noticed that the girl  8  the wheel with her hands. Li Ming watched her carefully and

was  9  to find that the girl had no feet. He looked at his own feet,"It's much  10  to be without shoes than

without feet." He thought. There was no reason for him to feel so sorry and sad. He went away and smiled,

thinking he was luckier.

在建设工程设计施工一体化/总承包合同中，承包人一般应当承担的主要义务有( )。

A．负责工程的协调与恰当实施
B．向发包人提供履行合同的条件
C．如果发包人单位要求终止合同后，没有承包人的同意，在一定时期内不得重新开始实施该工程
D．协助发包人申请有关许可、执照和批准

低碳钢、变形铝合金等塑性良好的金属适合于各种塑性加工。

音乐和文学诚然不会直接教你如何去解微积分方程，但是却能______你的文化背景，______你的想象力，______你的审美感，______你的精神境界，从而使你成为一个完整的、和谐的人。
填入横线部分最恰当的一项是( )。

A．拓展 丰富 提高 提升
B．丰富 提高 提升 拓展
C．拓展 提高 提升 丰富
D．丰富 提升 提高 拓展

轿车根据什么选用汽油标号，才能使发动机发挥出最佳的效能？