弹力产生的原因是由于物体发生了 ．弹簧测力计的原理是 ．
弹性形变；弹簧的伸长与所受拉力成正比
阅读短文，用适当的单词填空，完成短文。
You'll see a new d 1 at a hospital near London if you go there. He is very clever, b 2 he never speaks.
He can work 24 hours a day and never gets t 3 . He is one meter tall and has a face l 4 a TV screen. He is
Dr Robot. Doctors often need t 5 ask their patients a lot of questions. Kind doctors can only spend a few
minutes with each patient. But Dr Robot can ask a patient questions for a hour i 6 it is necessary. W 7 the
help of Dr Robot, a human doctor can have a lot of useful i 8 when he meets his patients.
How can Dr Robot do this? A computer "tells" him what to do. Dr Robot can do a lot of things people can
d 9 , though he can't completely t 10 the place of human doctors.
当α粒子穿过金箔发生大角度偏转的过程中，下列说法正确的是[ ]
A．α粒子先受到原子核的斥力作用，后受到原子核的引力作用
B．α粒子一直受到原子核的斥力作用
C．α粒子先受到原子核的引力作用，后受到原子核的斥力作用
D．α粒子一直受到库仑斥力，速度一直减小
