小明和小华分别用不同器材测量实心小木块（ρ_木＜ρ_水）和食用油的密度，请将实验过程补充完整．（ρ_水=1.0×10³kg/m³）．

小明利用细长针、量筒、足量水设计了以下实验步骤：

（1）①把适量的水倒进量筒中，记录此时水的体积V₁

②将木块轻轻放入量筒中，木块即将____ （选填“漂浮”“悬浮”或“沉底”），记录此时水面对应的刻度V₂；

③用细长针将木块浸没于水中，记录此时量筒的示数V₃，则小木块的密度的表达式为ρ_木=____ 　

（2）小华用两个注射器外筒及软管做成了连通器，两个针管内分别倒入水和食用油，液面静止后如图所示，右管中液体为____ ，小华用刻度尺测出水和油的分界面（右管中虚线位置）距离右管液面5cm，距离左管液面4.4cm，通过计算该食用油的密度ρ_油=____ kg/m³．

完形填空
   A little girl went to a hospital. “I want to 1 a miracle(奇迹).” “What?” said the doctor. “My brother is badly ill, 2 my daddy says only a miracle can save my brother.” “We don’t sell miracles here, little girl. I’m 3 but I can't help you,” said the doctor. “I have the 4 to pay for it.” said the girl.
The doctor’s brother asked, “What miracle does your 5 need?” “I don't know,” she answered. “My daddy can't 6 for it, so I want to use my money.” “How much do you have?” asked the man. “A dollar and a half.” “Well,”7 the man, “a dollar and a half can buy a miracle.”
That man was a very good 8. The operation(手术) was free and her brother became well. “What's the price 9 the operation?” her mom asked. The little girl smiled. She knew exactly how 10 a miracle was—a dollar and a half with the faith(诚意) of a little girl.

在神经系统中，兴奋是以电信号的形式沿神经纤维进行传导的，该信号称为（　）