【单选题】Some scientists think there might be more advanced civilizations on other planets because______.
A.
some planets support more advanced civilizations
B.
some civilizations have sent us signals we can't recognize
C.
the evolution of intelligence on other planets is unlike ours
D.
some planets in our galaxy are much older than the earth
【判断题】From the earliest documented accounts, ancient civilizations have explored the earth by sea.
【简答题】1-4 画出图1-1-4所示的液面闭环控制系统框图。 在系统框图中填空A____;B____;C____;D____; 调整过程:若流出液体的流量受外部干扰因素影响而增大,使实际液面高度____(上升或下降)而低于给定液面高度h,控制器便会产生一个____(正或负)的偏差信号,控制器的控制作用会使调节阀____(增加或减小)开度,使液面高度逼近给定液面高度。
【单选题】姐姐有9颗糖,妹妹有14颗,姐姐的比妹妹的( )
【简答题】Modern civilizations are as dependent on trees as ______.
【单选题】The use of money is not limited to high civilizations; actually many primitive peoples have moneys of their own.
【单选题】.下列选项中,哪个不是文化四层次里的( )
【判断题】All civilizations have a shared religion.
【简答题】Civilizations have grown and prospered in Rome for thousands of years, which is why Rome is nicknamed _______________