Hurry . and don't get wrong
what challenges did engineers and mechanics face while building railroads?

a. locomotives usually broke down before arriving at their destinations
b. engineers did not have the necessary materials to build railroads
c. the railroads had to pass over mountains and rivers
d. the american public was not interested in railroads

For 50 pointsfredrika's science teacher asked her to bring in three abiotic items from her backyard ecosystem. which of the following groups of items should she bring? a. a lightning bug, a plug of grass, and a wormb. a smooth rock, some red dirt, and an empty bird's nestc. a ladybug, a spider, and some water from a mud puddled. a caterpillar, a pine cone, and a piece of a robin's egg