【判断题】一般电源进线侧接通用变频器的端子R S T,调速电机接该变频器的UVW端子。( )
【简答题】设函数f(x)=ax 2 +bx+c(a>0)且f(1)=- a 2 . (1)求证:函数f(x)有两个零点; (2)设x 1 ,x 2 是函数的两个零点,求|x 1 -x 2 |的取值范围.
【单选题】MCS-51 系列单片机的定时器T0用作定时方式时,采用工作方式1,则初始化编程为______。
【单选题】Accordingly, ________ engineers face great challenges in using this technology to successfully manage solid waste
【单选题】李某,流产后出现月经不调,表现为月经周期正常,经期延长,伴下腹坠胀、乏力,疑诊断为黄体萎缩不全子宫内膜活体组织检查报告,支持诊断的是
【简答题】设函数f(x)=xlnx(x>0). (1)求函数f(x)的最小值; (2)设F(x)=ax 2 +f′(x)(a∈R),讨论函数F(x)的单调性.
【判断题】The first hijacked plane crashed into the north tower at 8:15.
【单选题】According to the passage, all of the following are advantages of humans over robots EXCEPT:
A.
humans can more accurately manage the data collected
B.
humans can apply critical thinking skills to new situations
C.
humans can typically stay in outer space for longer periods of time
D.
humans are more sensitive to environmental changes
E.
humans are better at preparing instrumentation for use in space
【简答题】定语从句可以分为两类:____性定语从句和____性定语从句。