① Link tag href attribute
② Script tags src attribute
③ Img tag src attribute
④ Ajax sends a request
⑤ transmission request form submission
⑥ a tag href attribute
⑦ Iframe 's src attribute
① Link tag href attribute
② Script tags src attribute
③ Img tag src attribute
④ Ajax sends a request
⑤ transmission request form submission
⑥ a tag href attribute
⑦ Iframe 's src attribute