const Title = (props) => <div className="card-title">{props.children}</div>;
const Body = (props) => <div className="card-body">{props.children}</div>;

class Card extends React.Component {
  static Body = Body;
  static Title = Title;

  render() {
    return <div className="card card-block">{this.props.children}</div>;
  }
}

const vdom = (<Card>
  <Card.Body>
    <Card.Title>What is love?</Card.Title>
  </Card.Body>
</Card>);

const mountNode = document.getElementById('react-root');
const root = ReactDOM.createRoot(mountNode);
root.render(vdom);