If you are weak _____ a subject, ______ and asking a teacher for advice can help.

If you are weak _____ a subject, ______ and asking a teacher for advice can help.

A．at; working hard                        B．in; work hard

C．at; work hard                          D．in; working hard

If you are weak _____ a subject, ______ and asking a teacher for advice can help.

1. A.
   at; working hard
2. B.
   in; work hard
3. C.
   at; work hard
4. D.
   in; working hard