有中子衍射技术中,常用热中子研究晶体的结构,因为热中子的德布罗意波波长与晶体中原子间距比较接近。已知中子质量为1.67× 10-27kg,普朗克常量为6.63×10-34J·s,则可以估算出德布罗意波波长为1.82×10-10m的热中子动能的数量为( )
A:10-17J
B:10-19 J
C:10-21J
D:10-24J
无论m为何值,点A(m,5﹣2m)不可能在( )
有关地理信息技术与地图的叙述,不正确的是( )
what ,be ,an ,last, some ,the, in ,your ,black ,my ,call, how
Hello, everyone. I ____ Frank Smith.Frank is my first name.My ____name is Smith.This is my schoolbag.It's ____. In it,you can see ____books and a pencil box. ____ is that? Oh,it is a watch. And ____ watch is yellow. It isn't____ . I found it ____ Class 7A. Is it ____? Please ____ Frank at 9556833.