What is the primary chemical protective mask in the us navy?

What is the name for the main idea behind the settling of western lands by americans in the early-1800s?

In ohio in 1872, the cleveland massacre was a violent labor dispute at standard oil refineries in cleveland. a takeover by standard oil of the refineries in cleveland. an attempt to stop standard oil from becoming a monopoly. a failed attempt by standard oil to take over other refineries.

Which of the following best describes the geography of oklahoma? a. extreme elevation differences b. varied ecological regions c. limited, mountainous geography d. flat rolling hills to below sea level areas