题目

下列函数中周期是π,且在(0, )上为增函数的是（    ）A.y=tan|x|            B.y=cot|x|C.y=|tanx|            D.y=|cotx| 答案：解析：可用排除法,B、A无周期性,D在(0,)上为单调减函数.答案：C完形填空： 　　Motor cars were first made in England just before 1900. The parts for the bodies and engines (发动机) 1 hand-made, and the cars built from these were made at a time. This 2 a long time and the cars 3 a lot of money. 　　Some of these old cars are 4 running and every year take part in a race 5 London to Brighten. 　　The car makers had to find a quicker and 6 way of making cars so that people 7 buy them. 　　Instead of 8 all the parts at their own factory, some car makers 9 other factories to do this. Then parts were 10 fitted (组装)together by the car makers. 　　 11 American whose name was Henry Ford found a quick way of making cars. He had a 12 of men who fitted together each part of a car. Then the men 13 to another car. Other men 14 the parts to them. When the cars were finished, they were 15 away and another line of cars was 16 . 　　Today the cars are 17 away by a moving track (输送带). Modem car-making factories are 18 large that each one is 19 a lot of factories close together. 20 of men and women work in each factory and make the many different parts of cars. 1． [　　] A．wereB．was C．isD．have been 2． [　　] A．spentB．kept C．tookD．gave 3． [　　] A．costB．spent C．boughtD．paid 4． [　　] A．yetB．still C．alsoD．too 5． [　　] A．ofB．in C．fromD．till 6． [　　] A．clevererB．clearer C．cheaperD．certain 7． [　　] A．couldB．must C．shouldD．had to 8． [　　] A．buyingB．selling C．mendingD．making 9． [　　] A．hadB．ordered C．askedD．made 10． [　　] A．notB．always C．onlyD．hardly 11． [　　] A．TheB．A C．AnD．/ 12． [　　] A．groupB．many C．fewD．little 13． [　　] A．moved awayB．moved off C．moved outD．moved on 14． [　　] A．threwB．explained C．showedD．brought 15． [　　] A．goneB．driven C．runD．put 16． [　　] A．givenB．noticed C．startedD．fitted 17． [　　] A．carriedB．brought C．drivenD．made 18． [　　] A．soB．such C．tooD．very 19． [　　] A．oftenB．true C．reallyD．likely 20． [　　] A．MillionB．Thousands C．A hundredD．A thousand