<span>He used heavily armed planes. </span>
Soldiers also made dugouts and funk holes in the side of the trenches to give them some protection from the weather and enemy fire. The front-line trenches were also protected by barbed-wire entanglements and machine-gun posts. Short trenches called saps were dug from the front-trench into No-Man's Land.
To cause a source to be biased means that it is influenced by your opinion or another factor that is not factual. Bias can take away from the credibility because it is not completely true, as a source should be.
Today, we use the Gregorian<span> calendar so I believe it's A. </span><span>the 12 month calendar</span>
