Which sentence below is a compound sentence?
a. when the train arrives and if ms. langlois is on it, she will be served with a subpoena.
c. the football game was cancelled because it was raining.
b. unless my girlfriend postpones her visit from calgary, i will not have time to study for my exam.
d. ottawa is the capital of canada, but toronto is the capital of ontario.

I think the answer is C or D. Hope this helped!

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."

the correct answer is d. in john paston's letter written friday, 14, 1476, he expresses his fear that he may have to go to war.

indeed, although the black death was ravaging europe, the pastons were relatively safe from it due to their social status as they were part of the landed gentry. it is clear that the vast majority of the victims of the pandemic were the poor. the reason why he is weary of having to go to war is because at the particular time england was also devastated by the war of the roses and paston, being a courtesan was inevitably involved.