Currently I am in Zhongshan, China now for business tour for 1 month and having single entry visa in to china.

I would like to Visit Macau for few days and come back to China again.

1) Can you please guide me if i need to re-apply for visa in to china again after ?
2) will the single entry visa expires after i leave and enter Macau ? or can i use same visa for coming back in to china ?

Appreciate your kind advise