no need to use break

Challenge [Selecting from many options with Switch Statements](https://www.freecodecamp.cn/challenges/selecting-from-many-options-with-switch-statements) has an issue.
User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36.
Please describe how to reproduce this issue, and include links to screenshots if possible.

My code:
```javascript
function myTest(val) {
var answer = "";
// 请把你的代码写在这条注释以下

switch(val){
case 1:
return "alpha";
case 2:
return "beta";
case 3:
return "gamma";
case 4:
return "delta";
}

// 请把你的代码写在这条注释以上
return answer;
}

// 你可以修改这一行来测试你的代码
myTest(1);

```