typewriter with constant pitch

例句：

1. 1. The typewriter was a popular tool for typing in the 19th century.
   打字机是19世纪流行的打字工具。
2. 2. She used to type all her homework on a typewriter.
   她过去经常用打字机打她的作业。
3. 3. He bought a new typewriter for his office.
   他为他的办公室买了一台新打字机。