用来体现经济变量与时间的变化关系的经济数学的内容为( )。
A.几何代数
B.线性代数
C.多元微分方法
D.采用微分方程或差分方程
参考答案:D
短文填空 阅读下面一段短文,然后在空白处写出适当的单词,单词首字母已经给出。[有的词请注意词形的变化!] (共12个空,做对一个得1分,共10分)
Everyone needs friends. We all like to feel close to someone. We can share 小题1:s with our friends and turn to them for help when we are in trouble. In a word, it is nice to have a friend to 小题2:t , laugh and do things with. Certainly, sometimes we need to be alone. We don’t always want people around. But we would feel 小题3:l if we never had a friend.
To make 小题4:f , you must be friendly. A cheerful person smiles. A smile always makes the others like you. Smile at someone and you are sure to get a smile 小题5:b from him.
Try to remember names. It 小题6:m your new friends feel happy when you call them by their names, 小题7:b you don’t forget them.
No two people are just the same. If you don’t agree with other people, you should still be friendly. Do not argue, but 小题8:d . You always lose friends if you argue too much. And you should think more of others than 小题9:o yourself. It’s good for teenagers to have one or a group of good friends. This is very 小题10: in children’s growing up, because friends can discuss things which are too difficult to say to their family members.
There’s more good news for people who have friends. They live 小题11:l than people who don’t have. Why? It could be that they小题12:a happier. Being happy helps you stay well and it could be good just knowing that someone cares about you.
下列对于表皮样囊肿的描述不正确的是
A.常因异物刺入后,皮屑经创道进入皮下,逐步缓慢生长而形成
B.多见于常摩擦的部位如手掌、指端、足跖、趾底等
C.病灶位于皮下或皮下组织
D.生长往往较快
E.偶可恶变为鳞状细胞癌