high-speed trains 高铁
train the dog 训练狗
train staff 培训员工
train of thought 思维脉络
A: How many trains are there to Paris today?
A：今天去巴黎的火车有多少趟？
B: There are about ten trains departing today.
B：今天大约有十趟列车出发。
1) 火车（复数）
2) 训练/培训（动词单三）
3) 一系列/一连串
1. 火车（复数）
2. 训练，培训
noun
1. More than one train; railway vehicles.
verb
1. To teach a person or animal a particular skill or behavior.