Question

there's a chemist in the high street改为否定句

Answer 1

答：我们认为There's a chemist in the high street.这个可以这样改为否定句：

There isn't a chemist in the high street.

Answer 2

回答和翻译如下:
There is not a chemist in the high street.
没有一个化学者在高街。(改为否定句)