地壳中含量最多的金属元素是[ ]
A、铝
B、钠
C、氧
D、硅
答案：A
_______ is said that _______ tourists visit the park every day .
A．That , thousands of
B．It , five thousand of
C．It , thousands of
D．This , three thousand
土石方填筑材料中，边坡稳定性最差的是黏土。（）
