Some students have trouble grammar while others have difficulty— new words.A. in; remember

问题补充：

Some students have trouble grammar while others have difficulty— new words.

A. in; remember

B. for; to remember

C. on; remembering

D. with; remembering

答案：

A. in; remember

B. for; to remember

C. on; remembering

(答案→)D. with; remembering

解析：考查trouble固定结构。Have some trouble with sth；have some trouble in doing sth做某事有困难。句意：一些学生在语法方面有困难，而其它学生在记忆新单词方面有困难。故D正确。