地球的半径为R,在北纬45°东经30°有一座城市A,在北纬45°东经120°有一

题型:填空题

问题:

地球的半径为R,在北纬45°东经30°有一座城市A,在北纬45°东经120°有一座城市B,则坐飞机从A城市飞到B城市的最短距离是______ (飞机的飞行高度忽略不计).

考点:球面距离
题型:填空题
若a≠0,且a、b互为相反数,
b
a
=______.
题型:填空题

有关血细胞分析仪堵孔的叙述不正确的是()。

A.堵孔分完全堵孔和不完全堵孔

B.完全堵孔仪器不能计数血细胞

C.不完全堵孔时,细胞计数慢而准确

D.长时间停用,盐类结晶可堵孔

E.抗凝剂量与全血不匹配或静脉采血不顺,有小凝块可引起堵孔

题型:填空题

第二节:短文改错(共10小题;每小题1分,满分10分)

此题要求改正短文中的错误。对标有题号的每一行作出判断:如无错误,在该行右边横线上划一个勾(√);如有错误(每行只有一个错误),则按下列情况改正:

该行多一个词:把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。该行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线上写出该加的词。

该行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。

Scientists around the world have been studying the warm      76.______

of waters in the Pacific Ocean being known as EL Nino. The       77.______                  

appearance of EL Nino is knowing to affect weather around        78.______           

world. Now scientists still do not completely understand           79.______           

them. Yet they find they can use it to tell the future in              80.______                      

different area in the world. The scientists write about              81.______

their recent work in the magazine Nature. Their computer          82.______                     

program can hardly tell when an EL Nino will appear. They         83.______

suggest that this could provide for an effective early warning        84.______

system and could prevent much of the disasters from happening.     85.______              

题型:填空题

新闻信息物化为报纸产品的最后一个环节是( )

A.“印”

B.“刷”

C.以“印”为主

D.“印”、“刷”并重

题型:填空题

失爆是指防爆型电气设备的隔爆外壳失去了()性或()性。

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