Pulmonary Surfactant. The force of surface tension in the lungs is so great that without something to reduce the surface tension, the airways would collapse after exhalation, making re-inflation during inhalation much more difficult and less effective. Collapse of the lungs is called alectasis.
Rules for Using Semicolons. A semicolon is most commonly used to link (in a single sentence) two independent clauses that are closely related in thought. When a semicolon is used to join two or more ideas (parts) in a sentence, those ideas are then given equal position or rank. Some people write with a word processor; others write with a pen or pencil. Use a semicolon between two independent clauses that are connected by conjunctive adverbs or transitional phrases.
Semicolons. It's no accident that a semicolon is a period atop a comma. Like commas, semicolons indicate an audible pauseâslightly longer than a comma's, but short of a period's full stop. Semicolons have other functions, too. But first, a caveat: avoid the common mistake of using a semicolon to replace a colon (see the Colons section). Incorrect: I have one goal; to find her. Correct: I have one goal: to find her. Rule 1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.