形成太阳直射点南北移动的根本原因是( )
A:黄赤交角存在
B:太阳回归运动
C:地球自转
D:地球公转
科学上常用元素符号左下角的数字表示原子的质子数,左上角的数字表示原子的中子数与质子数之和,如 613C表示核内有6个质子和7个中子的碳原子。下列关于 53131I和 53127I的说法中错误的是-( )
带电为+q的粒子在匀强磁场中运动,下面说法中正确的是( )
The Dress That Turns into a Coca Cola Machine This specially designed dress looks like a normal dress,but if you unfold it and cover yourself,you may look like a Coca Cola vending machine(自动售货机). Because there are many vending machines like that on the street,it must be easy for you to hide.If you feel that someone is following you or there is some danger,you can disappear within five seconds.But don't use it to scare your classmates.That'll be rude. The M-Dress is a nice black dress.It is also a mobile phone.It accepts a standard SIM card and allows the wearer to receive calls without carrying an actual(真实的) phone in their pocket or purse.You just need to bring your hand to your ear when you want to answer a phone call.When you finish talking and release your hand,the call will close.It is fashionable and useful.But it will certainly be an embarrassing moment when your dress rings in public. Air Conditioned Jackets You will love these air-cooled jackets in summer time when it is very hot outdoors.The jacket has fans that draw air in.The fan is powered by an inside battery.Now it is possible to spend nearly every second of your day with cool air.
埃里希•弗罗姆(1900~1980),美国著名____、____、____学派的重要代表人物。弗罗姆一生著述甚丰,内容广泛,主要著作有____、____、
____、以及____等。