The line is fuzzy.
line在句子中指的是“电话线路”，而fuzzy的意思是“模糊不清的”。这句话的正确意思是：“电话线路不清楚”。因此，当美国人说"The line is fuzzy."时，他/她要表达的意思就是:"The line is vague."、"We cannot hear clearlythrough the line."。
Benjamin: I'm sorry. Would you please say it again?The line is fuzzy.
Client: Sure. Can we meet at 2 p.m. this afternoon?
①I can't hear you.
②It's really strange since I had it repaired not long ago.
③It is always like that. I am tired of it.
④You can ask someone to check it.
vague adj. 模糊的，不明确的
A lot of the talk was apparently vague and general.
They have only a vague idea of the amount of water available.
Waite's memory of that first meeting was vague.