我应该如何使用react路由器v4处理查询路由？

import { BrowserRouter, Route, Switch } from 'react-router-dom';

function App() {
  return (
    <BrowserRouter>
      {/* 在这里定义你的路由 */}
    </BrowserRouter>
  );
}

function App() {
  return (
    <BrowserRouter>
      <Switch>
        {/* 在这里定义你的路由 */}
      </Switch>
    </BrowserRouter>
  );
}

function App() {
  return (
    <BrowserRouter>
      <Switch>
        <Route path="/" exact component={Home} />
        <Route path="/about" component={About} />
        <Route path="/contact" component={Contact} />
      </Switch>
    </BrowserRouter>
  );
}

import { Link } from 'react-router-dom';

function Navigation() {
  return (
    <nav>
      <ul>
        <li>
          <Link to="/">Home</Link>
        </li>
        <li>
          <Link to="/about">About</Link>
        </li>
        <li>
          <Link to="/contact">Contact</Link>
        </li>
      </ul>
    </nav>
  );
}