I am applying for a tourist visa but my tickets are for 45 days? how should i get it?

if i am to apply for normal L type do i need to show tickets for multiple entry as i don't have return tickets yet for my return within 30 days(i have confirmed return ticket for 45 days)? will it affect my application for tourist L type although i plan to travel to hong kong by train from guangzhou but haven't bought the tickets for that yet?