Hi,do you need any assistance?请问您需要帮助吗?
Hi,May I help you?我能为您服务吗?
Hi,how may I help you?我能为您服务吗?
May I know what you are looking for?请问您在找什么?
Is my pleasure to assist you.很荣幸能为您服务.(如果对方跟你说谢谢,你可以这样回答)
please come again.请再光顾.
hope to see you again.希望能在见到您