If you want to signal an interruption in a grammatical structure with a dash, you've got to keep track of the grammatical structure, and signal the return to the main structure with a second dash. Somewhat like colons, dashes are flexible enough to let you play with word order to create interesting sentences. Punctuation follows parentheses without a space. Question marks and exclamation marks Many students are reluctant to use question marks, but these are common and proper in academic writing. It would be nice to think that nothing would influence a scientist's search for the objective facts.
Reality often says otherwise. . . .
If you're reporting the end of a world war, feel free to use an exclamation mark. Otherwise, resist the temptation. As Lewis Thomas notes, exclamation marks tend to backfire. Italics and emphasis Italics and underlining both convey emphasis. Italics require good printing capability, while underlining is how one conveys emphasis in hand-written and typed work.