【单选题】What happens to the Internet and TV when the digital broadcasting system is adopted?
A.
They are being alienated.
B.
They are interdependent.
C.
They arebecoming distinctive.
D.
They are becoming similar.
【简答题】(文科)设向量 =(cos23°,cos67°), =(cos68°,cos22°), = +t (t∈R),则| |的最小值是____________ (理科)已知a>0,设函数f(x)= +sinx,x∈[-a,a]的最大值 为M,最小值为m,则M+m=__________
【简答题】向量 a =(cos23°,cos67°), b =(cos68°,cos22°), u = a +t b (t∈R). (1)求 a ? b ; (2)求 u 的模的最小值.
【简答题】The Voice of America began during the WorldWar II . When Germany was broadcasting a radio program to get international ___1___ , American officials believed they should ___2___ the German broadcast wi...
【多选题】关于反应级数的各种说法中不正确的是( )
【简答题】(文科)设向量 a =(cos23°,cos67°), b =(cos68°,cos22°), u = a +t b (t∈R),则| u |的最小值是______.
【单选题】计算cos23°sin53°-sin23°cos53°的值等于( )
【简答题】应对光伏产业中国制造2025的升级之路如何全面提升自己的综合专业能力?