[单选题]在ΔABC中,a=5,b=8,C=60°,则A.20B.-20C.20D.-20
[单选题]已知命题p:x∈[1,2],x2﹣a≥0,命题q:彐x∈R.x2+2ax+2﹣a=0,若“p且q”为真命题,则实数a的取值范围是[ ]A.-a≤a≤1B.a≤﹣2或1≤a≤2C.a≥1D.a=1或a≤﹣2
[单选题]The old man became very worried, standing at the gate, unable to find a man________he could turn forhelp. [ ]A. from whomB. at whomC. into whomD. to whom
[计算题]在△ABC中,角A、B、C所对的边分别为a、b、c,若向量=(cosB,sinC),=(cosC,-sinB),且,(Ⅰ)求角A的大小;(Ⅱ)若a=2,△ABC的面积S=,求b+c的值.
[单选题]下列说法正确的是A.“pvg为真”是“pAq为真”的充分不必要条件;B.设有一个回归直线方程为y=2-1.5x,则变量每增加一个单位,y平均减少15个单位;C.若ab∈[0.1,则不等式a2+b2<4成立的概率是—4;D.已知空间直线a.b.c,若a⊥b,b⊥c,则Qvc.
[单选题]命题甲:;命题乙:,则甲是乙的[ ]A、充分不必要条件 B、必要不充分条件C、充要条件D、既不充分也不必要条件
[单选题]在△ABC中,sin d 35,AB- AC=8,则△ABC的面积为( )A.3B.4C.6D.125
[单选题]Dozens of small cups were filled with oil to keep the lights burning _____ those who had died in the earthquake,A.in memory ofB.in favor ofC.in honor ofD.in search of
[单选题]已知命题P:vb∈[0.+∞),f(x)=x+bx +c在x∈0.+00上为增函数,命题Q:3x0∈{x|x∈z}?使 logx0>0,则下列结论成立的是(?)A.LPV-0B.P∧-0 C.PV-O D.P∧-0
[单选题]It was so dark in the cinema that I could hardly ________ my friend. A.turn outB.bring outC.call outD.pick out
[单选题]One _____ of being able to speak English is that you will have more job opportunities.A.aspectB.benefitC.wayD.value
[单选题]_____ what could happen, he did whatever he liked to and nobody could stop him.A.In case ofB.Regardless ofC.As a result ofD.In addition to
[单选题]I can’t say which type of tea tastes better. It’s just a(n) ______ of personal preference.A.affairB.matterC.varietyD.problem
[单选题]---I heard that you made a bicycle trip to the 2010 World Expo of Shanghai alone.---No. Actually, my friend Bob ________ me.A.accompaniedB.conductedC.instructedD.received
[单选题]The police suspected him of carrying drugs so they________his bag,but found nothing.A.looked upB.turned inC.searched forD.went through
[单选题]△ABC中,AB·BC=3△ABC的面积33S∈[,-则ABBC22夹角的取值范围是( )A.汇一4B.汇一46C.汇一6D.汇一A
[单选题]△ABC的三个内角A.B.C所对的边分别为a.b.c,给出下列三个叙述:①a:0.C=Sin a: sin 5. sinC②a.b. c=cos a: cos B: cos C③a:b:c=A.B- c以上三个叙述中能作为“△ABC是等边三角形”的充分必要条件的个数为( )A.0个B.1个C.2个D.3个
[单选题]The money ________ for this trip abroad has been ready.[ ]A. in advanceB. in needC. in chargeD. in trouble
[单选题]a=(2,3)|b=2√13,且∥则的坐标为( )A.(-4,6)B.(4,6)C.(6,-4)或(-6,4)D.(-4,-6)或(4,6)
[单选题]Anyone in the lab has to the following dos and don’ts.A.observeB.consultC.recognizeD.direct
[单选题]Eating too much fat can _____heart disease and cause high blood pressure.A.result fromB.contribute toC.devote toD.refer to