Questions

Like commas, semicolons indicate an audible pause — slightly longer than a comma's, but short of a period's full stop.

Rules for Semicolon ::

1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.

2. Use a semicolon before such words and terms as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc., when they introduce a complete sentence. It is also preferable to use a comma after these words and terms.

3. Avoid a semicolon when a dependent clause comes before an independent clause.

4. Use a semicolon to separate units of a series when one or more of the units contain commas.

Hence according to rule no. 2) option (C) He ate; however, he didn't sleep is correctly puctuated with a semicolon.

The aim of science is to get an understanding of the natural world, while the aim of technology is to use that understanding to improve people's lives. 

Hence, Advances in science can lead to new technology.

.mp3 is audio file extension.