题目:
滑闪放电的特征是介质表面通道中发生了()。
A.电场畸变
B.热游离
C.辉光放电
答案:
参考答案:B
滑闪放电的特征是介质表面通道中发生了()。
A.电场畸变
B.热游离
C.辉光放电
参考答案:B
The principal walked onto the platform and seated himself in a chair, _______ for answering questions.
A.prepared
B.being prepared
C.prepared
D.preparing
阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上涂黑。 The Keeper of the River An old man had been working for many years for a town.His job was to clear away natural waste from the pool water in the hills, which made up the lovely river flowing through the town nearby.Quietly and , the old man guarded the hills, the leaves and branches, and cleaned up the dirt that would have and polluted the fresh flow of water.The town soon became a popular attraction for tourists.Elegant swans (天鹅) floated along the clear river and the view was so beautiful words. Years passed.One evening the town met.As they reviewed the budget, one man's caught sight of the salary being paid to the seldom seen keeper of the river.He asked, "Who is the old man? Why do we to employ him? No one in town ever him. For all we know, the strange keeper of the hills isn't doing his job.His position isn't any longer." Then they voted to the man. For several weeks, nothing changed ... By early autumn, the trees began to their leaves.Small branches broke off and fell into the pools of the hills, the flow of the shining water.One afternoon, someone noticed a slight yellowish-brown in the river.A few days later, the water was much . Within another week, an oily something covered some sections of the water along the banks, and a terrible was soon sensed.Swans left, and so did the . The only thing that was now visiting the village was disease and sickness. Quickly , the town committee called a special meeting.Realising their huge mistake in , they rehired the old keeper of the river again, and within a few weeks, the river began to clear up.Swans and tourists came back again and new life returned to the small town in the Alps. Never ignore the seeming smallness of a task, job, or life.They may all make a .
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34岁女性,葡萄胎2次清宫后, * * 不规则流血持续存在,尿HCG(+)。
若B超发现子宫肌层呈蜂窝样改变应考虑为()
A.子宫内膜癌
B.绒癌
C.持续性葡萄胎
D.侵蚀性葡萄胎
E.胎盘部位滋养细胞肿瘤
关于神经纤维瘤的叙述,以下不正确的是()
A.神经纤维瘤来源于神经束膜、外膜或内膜等支持细胞
B.神经纤维瘤常为多发性
C.神经纤维瘤病常有家族倾向
D.神经纤维瘤患者皮肤常伴有淡棕色或深棕色色素沉着
E.神经纤维瘤有恶变倾向
溶血是指红细胞膨胀至破裂血红素逸出,其现象是溶液由不透明突然变成透亮。若在四支试管中均先加入0.3ml兔红细胞悬液,然后在四支试管中依次加入3ml下列溶液,溶血现象发生速率最快的是()。
A.氯化铵等渗液
B.醋酸铵等渗液
C.氯化钠等渗液
D.葡萄糖等渗液