The number of declared union strikes in the U. S. was about _______ in 1970, and declined to about ______ in2020 largely because _______________ . Group of answer choices 410 / 30 / both sides are harmed 380 / 30 / they are not allowed under federal law 380 / 100 / workers refuse to strike 380 / 30 / workers lose wages and benefits and employers lose production