观察下列图形(每幅图中最小的三角形都是全等的),请写出第个图中最小的三角形的个数有 个.
The first color TV set was considered by most people________this century. A. having been invented it B. one of whom invented C. who had invented it D.to have been invented
In order to work better in the future, each of us must first of all know our ______ and weaknesses. A. strengths B. benefits C. techniques
下图是与细胞分裂相关的坐标图,下列说法正确的是( ) A.甲图中CD段一定发生在有丝分裂后期 B.甲图中的AB段若发生在高等哺乳动物的精巢中,细胞肯定进
矿泉水中含有镁元素,其元素符号是( ) A.mg B.Ag C.Hg D.Mg
明代内阁和清代军机处的共同之处是( ) A.统领六部,处理各种政务 B.参与决策,并负责朝廷日常事务 C.参与机要政务,但没有决策权 D.负责各地
塑料废弃物的危害有( ) ①难以分解,破坏土壤结构,影响植物生长 ②污染海洋 ③危及海洋生物的生存 ④造成海难事件 ⑤破坏环境卫生,污