All my invention is the result of a deliberate and strict test.

我的一切发明都是经过深思熟虑和严格试验的结果。

youdao

I had never done a pure invention. All my invention is deliberate, strict test results.

我平生从来没有做过一次偶然的发明。我的一切发明都是经过深思熟虑，严格试验的结果。

youdao

I had never done a pure invention. All my invention is deliberate, strict test results.

我平生从来没有做过一次偶然的发明。我的一切发明都是经过深思熟虑，严格试验的结果。

youdao