目前用于复鞣铬鞣革的综合性能最好的植物鞣剂是（）。
参考答案：荆树皮栲胶
下列物质中属于化合物的是（ ）
A．镁
B．矿泉水
C．石灰石
D．高锰酸钾
— What is the model plane like?
— Well, the wings of the plane are ____ of its body. [ ]
A. more than the length twice
B. twice more than the length
C. more than twice the length
D. more twice than the length
