What kinds of scientific investigations involve making observations

True or false signed exact english is a system of manual communication that follows english syntax.

What can be inferred about shirley chisholm based on the fact that she protested the amount of money america spent on the vietnam war while suffering citizens were hungry, poorly educated, and living in unsatisfactory conditions? a. she had an intense interest in education because she had been a teacher before becoming a politician. b. she could identify with the suffering citizens because of her childhood growing up during the great depression. c. she had a sincere belief that the government should provide for the well being of needy americans before focusing on the needs of other countries. d. she disapproved of the military because of the dominant role of men in that institution.

But we pulled at the grill [on the ground] and it gave way. and then we saw iron rings as steps leading down a shaft into a darkness without bottom. … it was a great tunnel. its walls were hard and smooth to the touch; it felt like stone, but it was not stone. on the ground there were long thin tracks of iron, but it was not iron; it felt smooth and cold as glass. we knelt, and we crawled forward, our hand groping along the iron line to see where it would lead. but there was an unbroken night ahead. what is the most likely explanation for the walls described in the bold text?