Help yourself to celery and carrots and other vegetables.
请你们自己盛芹菜, 胡萝卜 和其他蔬菜。
Are you a native Chinese?
你是土生土长的中国人吗?
would be like trying to meet a friend in London without a pre-arranged rendezvous and absurdly wandering the streets in the hope of a chance encounter.