【单选题】
“不粘锅”饮具是在金属锅的内壁上涂一薄层聚四氟乙烯制成,下列各项对聚四氟乙烯的叙述中正确的是( )。
①
聚四氟乙烯的化学性质很稳定,正常使用时不会发生化学变化
②
聚四氟乙烯的分子内支链很多,且彼此缠绕,不会污染食物
【单选题】
聚四氟乙烯膜优点不包括
④
表面有50nm、特定孔隙,可以隔离成纤维细胞,孔的大小允许细胞及小血管长入,有利于血管源性细胞增殖
【单选题】
聚四氟乙烯膜缺点不包括
①
口腔软组织开裂造成膜暴露几率较高,可能导致感染
【单选题】
聚四氟乙烯(塑料王)为高分子化合物,属于()。
【填空题】
平行线l1:3x-2y-5=0与l2:6x-4y+3=0之间的距离为[填空1]
【单选题】
有定义语句“int a[][3]={1, 2, 3, 4, 5, 6};”,则a[1][0]的值是____。
【单选题】
已知:inta[][3]={1,2,3,4,5,6,7,8,9,0};则数组a的第一维的大小是()
【单选题】
向量空间<imgwidth="216"height="28"src="data:image/png;base64,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"/>的维数等于()
【单选题】
以下程序的运行结果是()。intfun(inta[4][4]){inti;for(i=0;ii++)printf("%2d",a[i][2]);printf("\n");}main(){inta[4][4]={1,1,2,2,1,9,0,0,2,4,0,0,0,5,9,8};fun(a);}
【单选题】
在建筑工程中,一般以()为假定水准面,设其高程为<img class="kfformula" src="data:image/png;base64,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" data-latex="\pm 0.000m"/>