I believe it's called a Geiger counter.
Answer:
D He gave lands in the east to a co-emperor.
Explanation:
Diocletian named Maximian as August, a type of co-emperor, who help him to manage the Roman Empire.
Answer:The expansion of the railroads in the late 1800s was instrumental in helping the US economy boom. It did this in two ways. First, the railroads created a tremendous amount of demand for goods and labor on their own. As the railroads were being built, they needed huge numbers of people to build them.
Explanation:
