【简答题】下列说法:①若f(x)=ax 2 +(2a+b)x+2(其中x∈[2a-1,a+4])是偶函数,则实数b=2; ② 既是奇函数又是偶函数; ③已知f(x)是定义在R上的奇函数,若当x∈[0,+∞)时,f(x)=x(1+x),则当x∈R时,f(x)=x(1+|x|); ④已知f(x)是定义在R上的不恒为零的函数,且对任意的x,y∈R都满足f(x·y)=x·f(y)+y·f(x),则f(x)是奇函数;...
【单选题】Tanya is planning a persuasive message. What should she do in her opening?
A.
Explain the purpose of the request completely.
B.
Ask a stimulating question.
C.
Show the value of her proposal.
D.
Focus on the sender's direct and indirect benefits.
【简答题】下列说法:①若f(x)=ax 2 +(2a+b)x+2(其中x∈[2a-1,+a+4])是偶函数,则实数b=2;②f(x)= 2009- x 2 + x 2 -2009 既是奇函数又是偶函数;③已知f(x)是定义在R上的奇函数,若当x∈[0,+∞]时,f(x)=x(1+x),则当x∈R时,f(x)=x(1+|x|);④已知f(x)是定义在R上的不恒为零的函数,且对任意的x,y∈R都满足f(x?y)...
【单选题】He talked to her in a (persuasive) manner.
【判断题】( )婴儿的动作发展是:0-1岁时以移动运动为主,1-2岁时从移动向基本运动技能过度。A. √ B. × C. D.