Which innovation made WWI casualties higher than any other previous war?

A)a new defensive tactic known as trench warfare

Trench warfare allowed the war to drag on for long periods of time because of the stalemates that ensue from the opposing armies refusing to give up the land under their controls, resulting in high casualties in no man's land.

answer; /// i believe that the correct answer is (d)the huang he river valley;

b. after i get up in the morning,

explanation:

after is a subordinating conjunction that introduces a time clause. time clauses are dependent clauses used to indicate when something happened.

the clause "after i get up in the morning" tells when the action in the main clause (drinking a cup of coffee) happens:

"after i get up in the morning, i drink a cup of coffee." it is the most logical choice of all.