Tom is a good boy and he writes in his class. A. carefulB. the most carefulC. carefullyD.

问题补充：

Tom is a good boy and he writes in his class.

A. careful

B. the most careful

C. carefully

D. the most carefully

答案：

A. careful

B. the most careful

C. carefully

(答案→)D. the most carefully

解析：句意：Tom是一个好孩子，他在他们班上是写字最认真的。最高级用于三者以上进行比较，其结构是“谓语动词+副词最高级+表示范围的短语或从句”（如all,of all,in …..）本题副词修饰动词所以 。应用carefully,而他是多音节的副词最高级要借助most carefully 构成，根据题意故选D。