光纤按按传输的模数分类,分为()和()。

题型:填空题

问题:

光纤按按传输的模数分类,分为()和()。

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题型:填空题
如图,矩形ABCD中,AB=4,BC=5,AF平分∠DAE,EF⊥AE于E,则CF等于 (   )

A.
B.1
C.
D.2
题型:填空题

对下列各溶液中,微粒的物质的量浓度关系表述正确的是(  )

A.某溶液中存在的离子只有Cl-、OH-、NH4+、H+,该溶液中离子浓度大小关系可能为c(Cl-)>c(NH4+)>c(OH-)>c(H+

B.0.1 mol•L-1(NH42SO4溶液中:c(H+)>c(NH4+

C.0.1 mol•L-1的HCl溶液与0.1 mol•L-1的NaOH溶液等体积混合:c(H+)+c(Na+)=c (OH-)+c(Cl-

D.0.1 mol•L-1 CH3COONa溶液中:c(Na+)>c(CH3COO-)>c(H+)>c(OH-

题型:填空题
完形填空 (共15小题; 每小题2分,满分30分)
阅读下面短文,掌握其大意,然后从下列各题所给的A、B、C和D项中,选出最佳选项,并在答题卡上将该题涂黑。
I climbed the stairs slowly,carrying a big suitcase,my father following with two more. By the time I got to the third floor,I was 1 and at the same time feeling lonely. Worse still,Dad 2 a step and fell,sending my new suitcases  3 down the stairs. “Damn!”he screamed,his face turning red. I knew trouble was ahead. Whenever Dad's face turns red, 4 
How could I ever 5 him to finish unloading the car without screaming at me and making a scene in front of the other girls,girls I would have to spend the rest of the  6  with?Doors were opening and faces peering out(探出),as Dad walked with difficulty close behind. I felt it in my bones that my college life was getting off to a(n) 7 start.
“Enter the room quickly,”I thought. “Get him into a chair and calmed down.” But then again,would there be a chair in Room 316?Or would it be a(n) 8 room?
  
Finally I turned the key in the lock and   9  the door open,with Dad still   10   about a hurting knee or something. I put my head in, 11 the worst. But to my 12 ,the room wasn't empty at all!It had furniture,curtains,a TV,and even paintings on the walls.
And there on a well­made bed sat Amy,my new roommate,dressed neatly. Greeting me with a nod,she said in a soft voice,“Hi,you must be Cori.” Then,she 13 the music and looked over at Dad. “And of course,you're Mr.Faber,”she said, 14 .“Would you like a glass of iced tea?”Dad's face turned 15  less red before he could bring out a “yes.”
I knew then that Amy and I would be friends and my first year of college would be a success.
1.A.helpless
B.lazy  
C.anxious
D.tired
2.A.took
B.minded
C.missed
D.picked
3.A.falling
B.rolling
C.dropping
D.coming
4.A.go ahead
B.look out
C.hold on
D.give away
5.A.lead
B.help
C.encourage
D.get
6.A.year
B.season
C.month
D.day
7.A.fresh
B.late
C.bad
D.unfair
8.A.small
B.empty
C.new
D.neat
9.A.knocked
B.forced
C.pushed
D.tried
10.A.thinking
B.complaining
C.talking
D.arguing
11.A.expecting
B.catching
C.finding
D.forgetting
12.A.regret
B.disappointment
C.astonishment
D.knowledge
13.A.turned on
B.turned down
C.turned up
D.turned away
14.A.questioning
B.wondering
C.smiling
D.guessing
15.A.helplessly
B.hurriedly
C.happily
D.obviously
 
题型:填空题
汽车在平直公路上以速度v0匀速行驶,发动机功率为P,牵引力为F0,t1时刻,司机减小了油门,使汽车的功率立即减小一半,并保持该功率继续行驶,到t2时刻,汽车又恢复了匀速直线运动(设整个过程中汽车所受的阻力不变).则图中能反映汽车牵引力F、汽车速度V在这个过程中随时间t变化的图象是(  )

A.

B.

C.

D.

题型:填空题

男性,45岁,心前区持续性疼痛1周,查体示重病容,体温38.8℃,血压100/70mmHg,颈静脉怒张,心界向两侧扩大,心率120次/分,心音弱,心律整,无杂音,心电图Ⅰ、Ⅱ、Ⅲ、aVF、aVL、V1至V5导联,ST段弓背向下抬高,T波倒置,最可能的诊断是()

A.急性下壁兼广泛前壁心肌梗死

B.变异型心绞痛

C.中间综合征

D.急性肺动脉栓塞

E.急性心包炎

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