Why was it difficult to make political changes in Mexico for most of the 20th century? * Elections were held infrequently.
The country lacked a powerful leader,
The government lacked a legislative branch.
One political party controlled the government.

Which of the following is defined as combinations of soil particles that vary in size and shape?

15 points need quick 1. looking at your graph and the geologic time scale during what period did this rock form? what is the age span of the rock, in millions of years? 2. this rock sample is limestone and shale. with what you know about rock formation, what type of environment did these organisms live in? 3. if some of these fossil samples were found in a rock also containing leaf fossils, could you use radiocarbon dating to determine the age of this rock? explain.

While viewing a topographic map, you notice a region in which the contour lines are very close together. what can you conclude about this region? a. it has a high population. b. it has a steep incline. c. it's near a political boundary. d. it contains a body of water.