As a result of the Columbian Exchange, the landscape of the Americas was significantly changed by the introduction of - Gold mining
Irrigation
New livestock
Terrace farming

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.

sorry i cant

the correct answer is d

a conference committee is a group of congress representatives appointed by the senate and the house to reach an agreement over a bill that had different versions in each chamber. this is due to the fact that, to pass a law. both the house and the senate must agree on the exact same content and wording of the bill to present it to the president.