如图所示,质量位m、电阻为R、边长为L的等边三角形ACD,在A处用细线悬挂于O点

题型:填空题

问题:

如图所示,质量位m、电阻为R、边长为L的等边三角形ACD,在A处用细线悬挂于O点,垂直于ACD施加一个垂直纸面向里的匀强磁场.当磁感应强度按规律B=Kt(K为常数)增强并且正好增大为B0时,CD边安培力是______,细线的拉力是______.

考点:磁场对通电导线的作用:安培力、左手定则
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发生在颈部正中线非牙源性发育性囊肿是()

A.鼻腭囊肿

B.甲状舌管囊肿

C.皮样囊肿

D.鳃裂囊肿

E.球上颌囊肿

题型:填空题

一个剧团在排练有关辛亥革命的剧目时,有如下几个场景,其中与史实不符的是 [ ]

A、 街头上出现“民主共和”的标语

B、 几艘外国军舰在长江上航行向革命党施压

C、 孙中山在灯下阅读《民报》

D、 报刊登出孙中山就任中华民国正式大总统的消息

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17——18世纪先后发生了英国革命、美国独立战争和法国大革命三次早期资产阶级革命。这三次革命的共同之处是 [ ]

A.都体现了封建制度过渡到资本主义制度的规律

B.都处死了国王

C.都体现了反抗殖民压迫、民族独立愿望的增强

D.都建立了资本主义政治制度

题型:填空题

用生姜贴涌泉穴可以治疗习惯性流鼻涕。

题型:填空题

If a mechanical aerator is installed in a fish pool, the water in the pool can be properly aerated. So, since John’s fish pool does not have a mechanical aerator, it must be that his pool is not properly aerated. Without properly aerated water, fish cannot thrive. Therefore, any fish in John’s pool will not thrive.
Which one of the following arguments contains an error of reasoning that is also contained in the argument above

A.If alum is added to pickle brine, brine can replace the water in the pickles. Therefore, since Pauls does not add alum to her pickle brine, the water in the pickles cannot be replaced by brine. Unless their water is replaced with brine, pickles will not stay crisp. Thus, Paula’s pickles will not stay crisp.

B.If pectin is added to jam, the jam will gel. Without a setting agent such as pectin, jam will not gel. So in order to make his jam gel, Harry should add a setting agent such as pectin to the jam.

C.If stored potatoes are not exposed to ethylene, the potatoes will not sprout. Beets do not release ethylene. Therefore, if Sara stores her potatoes together with beets, the potatoes will not sprout.

D.If a carrot patch is covered with mulch in the fall, the carrots can be left in the ground until spring. Without a mulch cover, carrots stored in the ground can suffer frost damage. Thus, since Kevin covers his carrot patch with mulch in the fall, the carrots can safely be left in the ground.

E.(E) If tomatoes are not stored in a dark place, their seeds sometimes sprout. Sprouted seeds can make tomatoes inedible. Therefore, since Maria does not store her tomatoes in a dark place, some of Maria’s tomatoes could be inedible.

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