One noteworthy point about creating a join expression is that every time you join from an expression, it returns a new join expression, as shown in Listing 9.

创建连接表达式需要注意的一个地方是，每次连接一个表达式时，都会返回一个新的表达式，如清单9所示。

youdao

Every time that I go to the gym I see a few people running on a treadmill and reading a book or a magazine, they watch TV and the expression on their faces tells me "Man, it's so boring!"

每次我去健身房都能看到一些人在跑步机上跑步，读书，看杂志，看电视。他们脸上的表情告诉我“哥们儿，太无聊了！”

youdao

Every time that I go to the gym I see a few people running on a treadmill and reading a book or a magazine, they watch TV and the expression on their faces tells me "Man, it's so boring!"

每次我去健身房都能看到一些人在跑步机上跑步，读书，看杂志，看电视。他们脸上的表情告诉我“哥们儿，太无聊了！”

youdao