在网上购买机票可以用英文表达为 "buy a plane ticket onpne" 或 "purchase a plane ticket onpne."

这个表达方式源自英语中的动词 "buy" 和 "purchase," 都表示 "购买," 并加上副词 "onpne," 表示在网上进行购买操作.

下面是一些使用这种表达方式的例句, 并附有中文翻译:

"I'm going to buy my plane ticket onpne because it's cheaper than buying it at the airport." (我要在网上买机票, 因为比在机场买要便宜.)
"I always purchase my plane tickets onpne because it's more convenient." (我总是在网上购买机票, 因为这样更方便.)
"I found a great deal on a plane ticket onpne, so I decided to buy it." (我在网上发现了一张很便宜的机票, 所以我决定买下它.)