下列正多边形的组合中,能够铺满地面(即平面镶嵌)的是 [ ]
A.正三角形和正四边形
B.正四边形和正五边形
C.正五边形和正六边形
D.正六边形和正八边形
答案:A
When I got to the checkout counter, I realized I didn't have enough money, so I kept _____ I really needed
and left the rest. [ ]
A. what
B. which
C. that
D. this
下列哪项不符合癫癎药物治疗原则 ()。
A.大剂量开始
B.单一用药无效者可联合用药
C.达疗效后继续正规用药
D.连续3年无发作后可缓慢减量
E.以小剂量维持后停药