（TypeScript，React）需要帮助来解释错误

Question

我是TypeScript的新手。我一直遇到两个具体的错误，希望从愿意提供帮助的人中得到一些澄清。我正在大量使用Material UI构建一个React应用程序。我直接从MUI的文档中复制了示例代码：
https://material-ui.com/components/selects/
（特别是Customized Selects源代码，TypeScript选项）

当我粘贴到vs代码中时，出现大量错误。有问题的两个是：

Cannot find name 'div'. ts(2304)

'FormControl' refers to a value, but is being used as a type here. ts(2749)

任何帮助将不胜感激！

MUI源代码：

import React from 'react';
import { createStyles, makeStyles, withStyles, Theme } from '@material-ui/core/styles';
import InputLabel from '@material-ui/core/InputLabel';
import MenuItem from '@material-ui/core/MenuItem';
import FormControl from '@material-ui/core/FormControl';
import Select from '@material-ui/core/Select';
import NativeSelect from '@material-ui/core/NativeSelect';
import InputBase from '@material-ui/core/InputBase';

const BootstrapInput = withStyles((theme: Theme) =>
  createStyles({
    root: {
      'label + &': {
        marginTop: theme.spacing(3),
      },
    },
    input: {
      borderRadius: 4,
      position: 'relative',
      backgroundColor: theme.palette.background.paper,
      border: '1px solid #ced4da',
      fontSize: 16,
      padding: '10px 26px 10px 12px',
      transition: theme.transitions.create(['border-color', 'box-shadow']),
      // Use the system font instead of the default Roboto font.
      fontFamily: [
        '-apple-system',
        'BlinkMacSystemFont',
        '"Segoe UI"',
        'Roboto',
        '"Helvetica Neue"',
        'Arial',
        'sans-serif',
        '"Apple Color Emoji"',
        '"Segoe UI Emoji"',
        '"Segoe UI Symbol"',
      ].join(','),
      '&:focus': {
        borderRadius: 4,
        borderColor: '#80bdff',
        boxShadow: '0 0 0 0.2rem rgba(0,123,255,.25)',
      },
    },
  }),
)(InputBase);

const useStyles = makeStyles((theme: Theme) =>
  createStyles({
    margin: {
      margin: theme.spacing(1),
    },
  }),
);

export default function CustomizedSelects() {
  const classes = useStyles();
  const [age, setAge] = React.useState('');
  const handleChange = (event: React.ChangeEvent<{ value: unknown }>) => {
    setAge(event.target.value as string);
  };
  return (
    <div>
      <FormControl className={classes.margin}>
        <InputLabel htmlFor="demo-customized-textbox">Age</InputLabel>
        <BootstrapInput id="demo-customized-textbox" />
      </FormControl>
      <FormControl className={classes.margin}>
        <InputLabel id="demo-customized-select-label">Age</InputLabel>
        <Select
          labelId="demo-customized-select-label"
          id="demo-customized-select"
          value={age}
          onChange={handleChange}
          input={<BootstrapInput />}
        >
          <MenuItem value="">
            <em>None</em>
          </MenuItem>
          <MenuItem value={10}>Ten</MenuItem>
          <MenuItem value={20}>Twenty</MenuItem>
          <MenuItem value={30}>Thirty</MenuItem>
        </Select>
      </FormControl>
      <FormControl className={classes.margin}>
        <InputLabel htmlFor="demo-customized-select-native">Age</InputLabel>
        <NativeSelect
          id="demo-customized-select-native"
          value={age}
          onChange={handleChange}
          input={<BootstrapInput />}
        >
          <option value="" />
          <option value={10}>Ten</option>
          <option value={20}>Twenty</option>
          <option value={30}>Thirty</option>
        </NativeSelect>
      </FormControl>
    </div>
  );
}