World war i introduced the following deadly warfare techniques. 1. tanks 2.machine guns 3.posionous gas 4.all of the above

congress also has implied powers, which derive from the necessary and proper clause of the constitution and permit congress "to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states.

the right answer for the question that is being asked and shown above is that: "their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.  " the  participant in european imperialism is being described below is that  their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.