F, I think you should take on the doubts and concur them!
Hello. Although you showed the book to which the question refers, you did not say which incident the question refers to, as there are many incidents covered in the book. This makes it impossible for your question to be answered, but I will try to help in the best possible way.
The main factor that points to the transition from old forms of war to new forms of war during the first world war was the use of technologies, mainly those driven by the industrial revolution, which gave the army a warlike power never seen before and allowed each army had access to fighter planes, tanks, submarines, toxic gases and others that did not exist in previous wars and that caused much greater destruction.
1/9=0.11111111 (and so on) so that would be the answer
The boxed words are a compound subject.
In a sentence talking about people, the people are subjects of that sentence. Subjects are basically what is being talked about.
Because there are two people being talked about, Bob and Al, the subjects are counted as one, or compounded. This just means that you read the sentence as [Bob and Al] instead of [Bob] and Al.
Compound verbs follow the same concept, but for action words. For example, “to sing and to dance”. However, in this case since the boxed words are subjects, they are a compound subject.
