第一句：When will the tour bus leave?
游览车什么时候开呢？
A: Excuse me. When will the tour bus leave?
请问游览车什么时候开？
B: In three minutes.
3分钟以后。
A: When will it get to the terminal?
什么时候到终点站呢？
B: 1: 30.
一点半。
第二句：How often does the bus come?
间隔多久来一趟公交车呢？
A: Excuse me. How often does the bus come?
请问多久来一趟公交车呢？
B: 20 minutes.
20分钟。
相关表达法：
What time does the tour bus leave? 旅游车什么时候出发呢？
观光游览车用英语说是：sightseeing bus 或者说 tour bus。