func get() {
    resp, err := http.Get("https://123/456.php?q=789")
    if err != nil {
        // handle error
    }
    defer resp.Body.Close()
    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        // handle error
    }
    html := string(body)
    doc := soup.HTMLParse(html)
}

func post() {
    resp, err := http.PostForm("https://123", url.Values{"SN": {word}})
    if err != nil {
        // handle error
    }
    resp.Header.Set("Content-Type", "application/x-www-form-urlencoded;application/json; charset=utf-8")
    defer resp.Body.Close()
    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        // handle error
    }
    html := string(body)
    doc := soup.HTMLParse(html)
}