边长为a的正方形截面如图所示,则该截面对y1轴的惯性矩Iy1为()。
A.A
B.B
C.C
D.D
参考答案:C
解析:
过C点做形心轴yC与y1平行,则IyC+b2A,IyC+b2A。
阅读下面短文,用文中括号内所给动词适当形式填空,必要时可加助动词。
Many young people like KFC's food.
These days, in China we can see fewer people 小题1:________(eat) in KFC restaurants when we walk past.Because some of their foods were not safe.The danger小题2: ________(come) from Sudan I.If a person eats too much of it, he 小题3:____________(get) cancer.Scientists 小题4:__________(find) Sudan I in some of KFC’s foods and asked it to stop 小题5:________(sell) them.Sudan I is a red dye.People use it 小题6:___________(color)oils but some people put it in foods to make them 小题7:___________(look) better.Now KFC restaurants 小题8:___________(sell) those foods again after scientists found no more Sudan I.If you 小题9:___________(eat) some of those foods last week, don't worry.There is very little Sudan I in them.It shouldn't 小题10:____________(be) a big problem.
与证券价格有关的“可知”资料可以分为三类。第一类资料:包括有关公司、行业、国内及世界经济的所有公开可用的资料,也包括个人、群体所能得到的所有私人的、内部资料;第二类资料:第一类资料中已公布的公开可用的资料;第三类资料:第二类资料中对历史证券市场价格进行分析得到的资料。这三种资料是一种包含关系。( )