答案：C
_______ 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
牛的结肠旋袢在形态上最大特点是形成（）.
A.结肠圆锥
B.结肠圆盘
C.双层马蹄铁形肠袢
D.以上均不对
