You can contact a junior college before the single move, because the single move means that you can only choose one school to apply for the exam, first choose the school and then choose the major, and you need to go to the local school to take the exam, so you can definitely contact the school or the professional admissions office staff before the exam. General admissions office staff are responsible for these things.
Matters needing attention in single move
The first voluntary school you applied for has nothing to do with the second voluntary school. It should be noted that the examination time of the two schools should not be on the same day.
The first and second volunteers are admitted from high to low, not the first and then the second. See the admission principles of each school specifically. Emphasizing the principle of admission means the first choice of merit-based admission, not parallel admission. In case you are not sure whether you are admitted to parallel volunteer, you can consult the teacher to be filled in by the school admissions office online (by telephone).
Refer to the above? Baidu encyclopedia-single move