As the communists closed in on saigon, the u. s. ordered air attacks against hanoi and other north vietnamese cities the evacuation of americans and south vietnamese from the city the mining of haiphong harbor to prevent enemy ships from attacking evacuation by boat of american military personnel via the mekong river

answer: this is because archeologists keep finding artefacts and ancient ruins dated more than 10000 to 15000 years, date around scientists said humans discovered language; which is at least mysterious as scientists always have said that is necessary to have a language to have architecture and some basic maths.

explanation: brainlest