导入了几次，一直报错。请问下怎么将ts转成浏览器的环境
Simulator: ERROR: TypeError: undefined is not an object (evaluating 'root._'), location: __node_modules/underscore/underscore.js:15:32
Simulator: STACK:
Simulator: __node_modules/underscore/underscore.js:15:32
Simulator: __define@__node_modules/underscore/underscore.js:1548:7
Simulator: __node_modules/underscore/underscore.js:1557:25