例句與造句

1. Originally an electric token system was used, which was replaced by half automatic signal locking and finally, as the country's first children's railroad, with automatic signal locking.
2. Originally an electric token system was used, which was replaced by half automatic signal locking and finally, as the country's first children's railroad, with automatic signal locking.
3. It's difficult to find signal locking in a sentence. 用signal locking造句挺難的