如何执行动态加载的JavaScript块？

const xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    const script = document.createElement('script');
    script.text = xhr.responseText;
    document.head.appendChild(script);
  }
};
xhr.open('GET', 'your-script.js', true);
xhr.send();

const xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    eval(xhr.responseText);
  }
};
xhr.open('GET', 'your-script.js', true);
xhr.send();