肾性水肿一般表现为（） A.双下肢对称性可凹性水肿 B.胸腔积液 C.晨起眼

设函数f（x）=x³-3ax+b（a≠0）．

（Ⅰ）若曲线y=f（x）在点（2，f（2））处与直线y=8相切，求a，b的值；

（Ⅱ）求函数f（x）的单调区间与极值点．

下列词语中有四个错别字，请找出来并加以改正。

一览无余　不可思异　喜出忘外　近在咫尺　络绎不绝

雍容典雅　不可救药　闲情逸至　花枝召展　安步当车

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离心管由多种材料制成，包括（）。

A.塑料

B.不锈钢

C.聚凝胶

D.聚丙烯

E.乙烯

如图所示，两根相距为l的平行直导轨ab、cd、b、d间连有一固定电阻R，导轨电阻可忽略不计；MN为放在ab和cd上的一导体杆，与ab垂直，其电阻也为R；整个装置处于匀强磁场中，磁感应强度的大小为B，磁场方向垂直于导轨所在平面（指向图中纸面内）；现对MN施力使它沿导轨方向以速度v（如图）做匀速运动；令U表示MN两端电压的大小，则（　　） A．U=vBl，流过固定电阻R的感应电流由b到d B．U=vBl，流过固定电阻R的感应电流由d到b C．U=vBl，流过固定电阻R的感应电流由b到d D．U=vBl，流过固定电阻R的感应电流由d到b

Tidiness

Tidiness means keeping things out of sight and yet available when wanted. It implies that there is a (1) for everything and that each thing used finds its way (2) to its place by a continuos process, not by a spasmodic (3) . The process depends, however, upon the drawer, cupboard and storage (4) being provided, for lack of which one things may literally have (5) place to go. Like the perambulator and trolley, the luggage and the golfclubs (6) be homeless. The same may be true of the deck-chairs (7) the bulkier plastic toys. As there is no place for them, it is no (8) telling people to put them away. The architect who thus economises on (9) space is apt to claim that a good-sized sitting-room is (10) result. What advantage is there in that, however, (11) half the living-room has to be used for storage The aesthetic (12) depends, in turn, upon storage space. (13) it may be true that no house ever had cupboards enough, (14) are some houses which have practically no cupboards (15) all. In these our choice must lie between chronic (16) and ruthless destruction. That is not to say, however, (17) cupboard space will itself create tidiness. Some people (18) happier, it would seem, in chaos. There is the question, furthermore, (19) the cupboards themselves are tidy. That (20) has been swept out of sight is no proof, in itself, that everything can be found.