阅读理解。 Before 1900, many theories existe

题型:阅读理解

问题:

阅读理解。

     Before 1900, many theories existed as to the cause of yellow fever (黄热病). Some doctors were sure the

disease was air-born; others felt that it was spread from person to person. Dr. Carlos Finlay, a well-known

Cuban doctor of that time, had long held the theory that it was caused by the bite of mosquitoes (蚊子). But

neither the pubic nor the doctors then accepted his idea.

     Despite this, Walter Reed, an American doctor sent to study yellow fever in Cuba, went to talk with Finlay.

Reed, after reading a lot on the subject, had begun to think that Dr. Finlay might be right. Then Reed and his

comrades set to work at once. Outside Havana, they set up a laboratory and began experiments to test the

theory. The experiments were successful. Now we know: A period of about two weeks must pass before a

mosquito, after feeding on a sick person, could infect another person. The sick person had to have yellow

fever a certain number of days before the mosquito biting him was able to carry the disease.

1. Before 1900,many people didn't think yellow fever was spread _____. [ ]

A. by air

B. by getting in touch with the patient

C. by the bite of mosquitoes

D. by dirty water

2. What is true according to the passage?

[ ]

A. Reed agreed with Finlay after his talk with him.

B. Reed proved the theory by reading a lot of articles.

C. Reed proved the theory in his American lab.

D. Reed scientifically proved the theory.

3. Who first realized the actual cause? [ ]

A. The public.

B. Reed.

C. Finlay

D. Doctors

4. A person comes down with yellow fever because he has been bitten _____. [ ]

A. by a mosquito

B. by a mosquito that has bitten a patient

C. by an infected mosquito

D. by a mosquito that has bitten a patient of some days

5. What is the possible title of the passage? [ ]

A. Reed, an Outstanding Doctor

B. Several Theories on Yellow Fever

C. Fight Against Yellow Fever

D. The Cause of Yellow Fever

考点:健康环保类阅读
题型:阅读理解

小明设计了如图1所示的实验装置来探究不同物体在木板上所受摩擦力的大小。

将物体放置在水平的长木板上,物体与木板表面粗糙程度不变,导电性能良好的弹簧其右端与物体及滑动变阻器R1滑片P相连(不计滑片与滑动变阻器线圈间的摩擦;滑动变阻器的阻值随长度均匀变化;探究过程中,滑片P始终在a、b间),弹簧的左端固定在墙壁上。当木板沿箭头所示的方向匀速运动时,物体和木板间发生相对滑动,物体处于平衡状态时,电流表的示数稳定不变,物体和木板间的摩擦力也不变。换用质量不同的物体,重复上述实验,发现电流表的示数随所放置物体的质量的变化而变化,不同物体所受的摩擦力f不同,滑动变阻器R1的阻值也不同。若物体所受摩擦力f与滑动变阻器R1的阻值的关系如图2所示,电流表的量程为“0~0.6A”,电源电压为3V。问:

(1)当滑动变阻器的滑片P指向b端时,为了保护电流表不致损坏,电阻R0的阻值至少为多大?

(2)若电阻R0的阻值为10Ω,某一物体在木板上处于平衡状态时,电流表的示数为0.2A,该物体所受的摩擦力是多少?

(3)当电路中电流表的示数变大时,不同的物体所受的摩擦力发生了什么变化?

题型:阅读理解

某同学为了验证海带中含有碘,拟进行如下实验,请回答相关问题。

(1)第1步:灼烧。操作是将足量海带灼烧成灰烬。该过程中将使用到的硅酸盐质实验仪器有   (填代号、限填3项)。 

A.试管 B.瓷坩埚 C.坩埚钳 D.铁三角架 E.泥三角 F.酒精灯 D.烧杯 H.量筒

(2) 第2步:I-溶液的获取。操作是                                          

(3)第3步:氧化。操作是依次加入合适的试剂。下列氧化剂最好选用    (填代号)。

A.浓硫酸        B.新制氯水        C.KMnO4溶液        D.H2O2

理由是                                                    

(4) 第4步:碘单质的检验。操作是取少量第3步的溶液,滴加淀粉溶液,如果溶液显蓝色,则证明海带中含碘。

题型:阅读理解
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题型:阅读理解

患者,男性,55岁。体检时胸部后前位片发现右上肺一块状阴影,其中有1.0cm×1.5cm的不规则偏心空洞,内壁凹凸不平,壁厚。首先应考虑

A.空洞性肺结核
B.肺癌
C.肺脓肿
D.肺囊肿

题型:阅读理解

患者外阴痒1周,查 * * 黏膜覆以膜状物,擦除后露出红肿黏膜面,正确的处理应是 ()。

A.局部用克林霉素软膏

B. * * 内放置达克宁栓

C. * * 内放置甲硝唑片

D. * * 内放置尼尔雌醇片

E.外阴部用0.5%醋酸液洗涤

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