What are the explicit equation and domain for an arithmetic sequence with a first term of 7 and a second term of 3? A. an = 7 − 4(n − 1); all integers where n ≥ 1 B. an = 7 − 4(n − 1); all integers where n ≥ 0 C. an = 7 − 3(n − 1); all integers where n ≥ 1 D. an = 5 − 3(n − 1); all integers where n ≥ 0

2. a land bridge connected asia and north america thousands of years ago.

4. crossing the land bridge would have been simple for the first migrants.

5. people might have crossed a land bridge while hunting animals.

rome's central location made it a center for trade through out the mediterain.

rome's lack of natural resouces encourgaged expansion and rome's geography priotected the city from invasion.