我是reactjs和material ui的新手，我想在导航栏中创建一个下拉列表

import React from 'react';
import { AppBar, Toolbar, Typography, Select, MenuItem } from '@material-ui/core';
import { makeStyles } from '@material-ui/core/styles';

const useStyles = makeStyles((theme) => ({
  select: {
    marginLeft: theme.spacing(2),
    minWidth: 120,
    color: 'white',  // 设置下拉列表文字颜色为白色
  },
}));

const Navbar = () => {
  const classes = useStyles();

  return (
    <AppBar>
      <Toolbar>
        <Typography variant="h6">My App</Typography>
        <Select className={classes.select} value="">
          <MenuItem value="">请选择</MenuItem>
          <MenuItem value="option1">选项1</MenuItem>
          <MenuItem value="option2">选项2</MenuItem>
          <MenuItem value="option3">选项3</MenuItem>
        </Select>
      </Toolbar>
    </AppBar>
  );
};

export default Navbar;