about train ticket

Normally 4 days, and 10days duiring the May 1st, Oct.1st and Spring Festival.

ten days

7

。。。不是问英文问题吗？？
学生订票可以提前十天。
如果不是旺季，就算只提前三天也是有的

“我想知道预定一张火车票要多久。”
原句可能漏了how应为：
I wanna know how long i can book a train ticket advanced.

wanna know想知道
how long多久
book...advanced 预定 book：预定；advance：把...提前；advanced：提前的

Generally speaking,4 days in Beijing.(including the speaking day)