Which were causes of the US entry into World war 1 ? select all that apply.

a. Germany threatened to invade the United the Unites States?
b. Germany refused to trade with the United States.
c. The Zimmermann Telegram angered US leaders.
d. The sinking of the Lusitania killed American civillians.

Why did the treaty of paris strain the american alliance with the french? 1.the french had expected to control the negotiations. 2.the french were upset with the generous boundaries granted to the united states. 3.the french lost many of their colonies in the negotiations. 4. the french had supported the british throughout the war.