关于电场强度和电场力,下列说法正确的是( ) A.由E=Fq知,电场中某点的场强

题型:选择题

问题:

关于电场强度和电场力,下列说法正确的是(  )

A.由E=

F
q
知,电场中某点的场强大小与放在该点的电荷所受到的电场力的大小成正比,与电荷的电荷量成反比

B.由E=

F
q
知,电场中某点的场强方向,就是放在该点的电荷所受到的电场力方向

C.在E=

F
q
中,F是电荷q受到的电场力,E是电荷q产生的电场的强度

D.由F=qE可知,电荷q受到的电场力的大小,与电荷的电荷量成正比,与电荷所在处的电场强度的大小成正比

考点:电场强度的定义式
题型:选择题

It is a cold and dry winter morning. When you wake up, you feel that your throat hurts. You begin to sneeze and later you may cough. You must have a cold! Wait a moment. Could it just be a common cold or the flu (流感) that’s been going around?

A cold gives you a runny nose and cough. But it’s usually easy to deal with. Some take medicine while others drink herbal tea or chicken soup. Usually you feel better after a week.

On the other hand, the flu can be much more dangerous. It usually gives you fever. Sometimes it can cause death. According to an American magazine, the worst flu killed about 50 million people from 1918 to 1919.

Don’t worry. If you get a flu vaccine (疫苗), it can stop you from getting the virus (病毒). Flu vaccines work by giving the body a small amount of flu viruses. This causes your body to develop antibodies (抗体). So next time you get the flu, the antibodies should help you.

The flu virus changes every few years. Therefore, there are so many types of flu, such as H1N1 and H5N1. The antibodies for one type of flu can’t help us against all types of flu. That’s why we need to get the vaccine every year.

However, good health habits may also help stop you developing a cold or flu. Washing your hands often helps stop you from getting viruses. It is also important to get regular exercise and eat healthy food. All these can help you strengthen your immune system (增强免疫系统).

小题1:If you have a common cold, usually you’ll feel better after ________.

A.a week

B.two weeks

C.ten days

D.twenty days小题2:According to the passage, which is TRUE of the flu?

A.It first happened in 1919.

B.It usually doesn’t give you fever.

C.It is easy to deal with.

D.It can kill people sometimes.小题3:If you get a flu vaccine, ________.

A.it can’t stop you from getting the flu virus

B.it won’t cause your body to develop antibodies

C.your body will develop antibodies

D.your body will get a large amount of flu viruses小题4:We need to get a flu vaccine every year because ________.

A.we probably have a cold in winter

B.the flu virus changes every few years

C.the flu is very dangerous

D.you don’t need to take any medicine after that小题5:The following ways can help stop the flu EXCEPT ________.

A.staying indoors

B.getting regular exercise

C.eating healthy food

D.washing our hands often

题型:选择题

(10分)环境保护

阅读图文资料,完成下列问题。

溯江而上,干流、支流多呈深不见底的墨色,黑!稍靠近江边,一股刺鼻气味就扑鼻而来,臭!河水重度污染,难觅鱼虾踪影,毒!沿河两岸,随处可见一堆堆的垃圾,苍蝇缭绕,脏!这一幕幕惨状,就是广东潮汕平原三大河流之一练江的现状。

(1)简述河流污染的危害。(6分)

(2)概括该河流污染的特点。(4分)

题型:选择题

男性,8岁。突起畏寒、发热、头痛、呕吐、皮肤瘀斑6小时于12月10日入院。查体:T40℃,P142次/分,BP61/49mmHg,神清,四肢厥冷,脉搏细速,周身皮肤可见大量瘀点、瘀斑,克氏征(-)、布氏征(-)。血常规:WBC24×109/L,NE85%,L15%。

为明确诊断最简单快速的检查方法是()

A.血培养

B.皮肤瘀点瘀斑涂片

C.脑脊液涂片

D.脑脊液培养

E.咽拭子培养

题型:选择题

甲公司向美国乙开证行发出通知,说明汇票上存在欺诈,而乙开证行兑付了汇票。乙开证行的行为应如何认定

A.乙开证行应对甲公司承担损害赔偿的责任,因甲公司已通知了乙开证行汇票上存在欺诈

B.只要单证表面相符,并构成善意行为,乙开证行不负任何责任

C.乙开证行接到甲公司的通知后应立即禁止款项的兑付

D.乙开证行无权禁止款项的兑付,只有有管辖权的法院可以禁止款项的兑付

题型:选择题

关于串行的正确理解是()。

A.一次可发送或接收一个字符的数据

B.一次可发送或接收一个字符中的一位

C.在发送数据时,数据的位是一位一位顺序传送的,接收时也是一位一位顺序接收的

D.在发送或接收过程中,数据是连续发送或接收的

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