to get the reader's attention
audience.
The most professional tone for your writing
Depending on the type of writing, you can usually use an exclamation point in a heading. However, it is not considered professional for most academic writing, such as essays, articles, etc.
use of idioms
The most personal type of writing uses the pronoun I.
An em dash is the width of an m. Use an em dash sparingly in formal writing. In informal writing, em dashes may replace commas, semicolons, colons, and parentheses to indicate added emphasis, an interruption, or an abrupt change of thought.
If you wish to express that something happens in January, February, March and April, you could use a dash to express this rather than writing out each month. It would look like this: January-April.
If you are classifying "dash" as hyphen, you use it such as: The One-of-a-kind Hat was sold within the first hour." This is used to make multiple words one. There is also another "dash" that could be used as "I might sure if i could--or even would--do such a thing." This is used to add detail.
The use of Voice
audience.
All motherboards use it effectively, although you may want to consider an Asus motherboard, such as the P5B.
It was the best material available at the time, that did the job most effectively.
The most professional tone for your writing
Whatever you can use effectively. Most shotgunners in the US opt for a 12-Gauge, but be a sport and use a .410, with deer slugs.
A dash represents an abrupt shift in a sentence. It separates a clause or phrase from rest of the sentence, either for emphasis or to introduce a phrase inside of parenthesis. Dashes may also be used to separate quoted material from its author.There are two types of dashes, the em and en dash. An en dash can be used for time periods (eg. June, 2005-March 2011) whereas an em dash is used as a comma replacement in certain instances of writing.
to get the reader's attention
Most people Understand