"The dog dropped in again at his heels, with a tail drooping discouragement, as the man swung along the creek bed. The furrow of the old sled trail was plainly visible, but a dozen inches of snow covered the marks of the last runners. In a month no man had come up or down that silent creek. The man held steadily on."

This description allows readers to visualize the desolation of the trail.

Explanation:

The dog dropped in again at his heels, with a tail drooping discouragement, as the man swung along the creek bed. The furrow of the old sled trail was plainly visible, but a dozen inches of snow covered the marks of the last runners. In a month no man had come up or down that silent creek. The man held steadily on."

This description allows readers to visualize the desolation of the trail.

answer; researchers typically cannot control people's sexual behaviors as would be necessary in an experiment;

every society, in order to meet the needs of it's people, has to answer three basic questions:

- what should we produce?

- how should we produce it?

- for whom should we produce it?

this questions must be answered in order to, option b, aid in production decisions.

every country can't produce everything, no matter how rich their land is. it may be a matter of technology, resources or geographical conditions. so, these three questions must be resolved in order to get the most of the production of each land.

hope this !