He taught them discipline and military strategies used by other armies in order to help them become more professional.
A. is a duty of congress. They can say a law is unconstitutional based in their views on the law but they cant declare one unconstitutional. But the President can declare a law unconstitutional and change it.
D, because it's a full sentence.
Spain which was not on the gold standard did not have a substantial decline from 1929 to 1933 as the US,Germany and many other countries endured a Contraction.
