___ he came to study in the university, he has made much progress in the study of English.

1. A.
   While
2. B.
   When
3. C.
   Since
4. D.
   After

___ he came to study in the university, he has made much progress in the study of English.

A. While               B. When             C. Since             D. After

___ he came to study in the university, he has made much progress in the study of English.

A. While               B. When             C. Since             D. After

___ he came to study in the university, he has made much progress in the study of English.

A. While               B. When             C. Since             D. After

___ he came to study in the university, he has made much progress in the study of English.

A. While               B. When             C. Since             D. After