【单选题】In the last paragraph, what is meant by 'cognitive cost'?
A.
the amount of time that the writer spends writing a report
B.
the reader's unwillingness to make an effort to understand a report
C.
the amount of time that the reader spends reading any report
D.
the writer's difficulty in presenting reports in an easily-understood style
【判断题】对新购调速器需要先进行参数自动优化然后才能进行调速器的软件组态。 ( )
【单选题】The main idea of paragraph three is that ________.
A.
most people feel life is easy
B.
the writer feels life is easy
C.
the writer likes to complain about his problems
D.
most people complain about how hard their lives are
【简答题】一质点沿半径R=1m的圆周运动,运动学方程为 (SI),其中k为常量。已知t=2 s时,质点速度值为24 m/s,求t=l s时质点的加速度大小以及加速度与法向的夹角。