一种生物个体中，如果隐性个体的成体没有繁殖能力，一个杂合子（Aa）自交，得子一代（F1）个体．在F1个体只能自交和可以自由交配两种情况下，F2中
对于支票的理解，正确的是（ ） ①支票是国家发行的，强制流通的价值符号②支票是从商品中分离出来固定地充当一般等价物的商品③支票是活
读图，回答下列问题 (1)图中甲是 板块，乙是 板块，丙是______板块。 (2)C是______海，这里的面积在不断______。从图中板块运动状况推测
下列四组线段中，不构成比例线段的一组是（ ）A.1cm, 3cm, 2cm, 6cm B.2cm, 3cm, 4cm, 6cm, C.1cm, cm,cm,cm, D.1cm, 2cm, 3cm,
由动点向圆引两条切线，切点分别为，则动点的轨迹方程为 。
Let’s hope that this is the first step _____ peace. A. in B. on C. for D. towards
It was on October 1st ____ new China was founded. A. which B. when C. as D. that
After years of hearing drivers complain about scratches (划痕) on their cars, Japan’s Nissan Motor Company has officially announced the next big thing--a paint that not only resists scratches and
的相反数是（ ）