The US has to have policy to declare war. Right now Trump took an aggressive step to send a message to Syria with the world ears especially Russia and Iran to draw a RED LINE on what will provoke the US to use any and all means to prevent chemical use.
Congress votes to declare war but the President as commander and chief can act on his own wearing that hat. It it is not a. Act of war unless Congress votes it so,
So important yet blurred with drone strikes. Limited "messaging" air strikes. It tends to be more semantics.
Answer 4 is the correct one.
Complicated instruments can possibly produce unreliable data depending on if they were used correctly, but they don't always do so.
Simple instruments like rulers can produce unreliable data if the data required is extremely precise, such as decimal measurements, but larger measurement values are typically fine.
More expensive equipment doesn't necessarily mean that it's better, it's just what the manufacturer decided to price the equipment at.
Depending on the situation, different equipment can be better, from a ruler to a caliper.
