Body language shows all kinds of feelings and is sometimes more important than spoken language.A smile is a usual facial expression----it shows that you are friendly to others. However, it does not always mean that you are happy. A smile can hide other feelings, like anger, fear, or worry.
In most countries, nodding the head up and down shows agreement, while shaking the head means that you do not agree, or that you would not like to do something. If you stand holding your arms across your chest, you may be protecting yourself---just from a conversation you do not want! If you sit looking at the person you are talking to and then turn toward to him, it shows that you are interested. If you roll your eyes and turn your head away, most likely you do not believe what you are hearing, or you do not like what you hear.
小题1:Body language shows__________.
A．all kinds of feelings
B．some special feelings
C．nothing
D．only happy feelings小题2:When a person smiles, ______________.
A．it always shows he is very happy
B．it always means he hides some feelings
C．there may be some other feelings behind the smile.
D．it shows he is angry, worried or frightened.小题3:______________, nodding heads up and down shows he agrees with you.
A．In most countries
B．In all countries
C．In some countries
D．In Western Countries小题4:If a man stands holding his arms across his chest, it means __________.
A．he wants to protect himself from a conversation he doesn’t want
B．he is very interested in the conversation
C．he is pleased with the man he is talking to
D．he wants to know more about the man he is talking to
圆心O与坐标系的原点重合的圆形区域，如图所示，在圆心O有一喷枪可在xOy平面内沿各个方向喷出初速度为v0=1 m/s，质量为m=l×10-6 kg，带电量为q=-1×10-8 C的油滴。圆形区域内的匀强电场方向沿-y方向，电场强度E=8×102 N/C。（g取10 m/s2，不考虑油滴间的相互作用） 
