for the boy to talk with his mouth full!A. What bad manners they areB. How bad manners the

问题补充：

for the boy to talk with his mouth full!

A. What bad manners they are

B. How bad manners they are

C. What bad manners it is

D. How bad manners it is

答案：

A. What bad manners they are

B. How bad manners they are

(答案→)C. What bad manners it is

D. How bad manners it is

解析：考查感叹句。What后面感叹的内容要是名词或者名词短语；how感叹的要是形容词，副词或者形容词副词短语。句意：对男孩来说嘴巴里满满地说话是没有礼貌的。故C正确。