day20-21/task2.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Day20-21</title>
  <style>
    select {
      display: none;
    }
  </style>
</head>
<body>
  <label>
    <input id="school" name="status" type="radio">
    School
  </label>
  <label>
    <input id="company" name="status" type="radio">
    Company
  </label>

  <select id="school-select">
    <option>北京邮电大学</option>
    <option>黑龙江大学</option>
    <option>华中科技大学</option>
  </select>

  <select id="company-select">
    <option>百度</option>
    <option>爱奇艺</option>
  </select>
  
  <script>
      function showSchool(event) {
          document.querySelector("#school-select").style.display = "inline-block";
      }
      function showCompany(event) {
          document.querySelector("#company-select").style.display = "inline-block";
      }
      function hiddenSchool(event) {
          document.querySelector("#school-select").style.display = "none";
      }
      function hiddenCompany(event) {
          document.querySelector("#company-select").style.display = "none";
      }
      document.querySelector("#school").addEventListener("click", showSchool);
      document.querySelector("#school").addEventListener("click", hiddenCompany);
      document.querySelector("#company").addEventListener("click", showCompany);
      document.querySelector("#company").addEventListener("click", hiddenSchool);
  </script>
</body>
</html>