Ứng dụng của quy luật thích ứng trong quản lý cảm xúc??

Does anyone know the answers for questions 1-4? plz me out if you know

What was different about warfare in the early 1800s and early 1900s?

Which characteristics are true of the arabian desert? choose all answers that are correct.has land mostly below sea levelcovers almost the entire arabian peninsulacontains the largest sand sea in the worldhas very few people living there