The main reason that the Constitution did not proclaim all men to be free and equal is because of the issue of slavery. Many of the Founding Fathers were slaveowners, including George Washington. The Founding Fathers did not want to lose the support of southern states when it came time to ratify the Constitution.
"Planting trees throughout Sahel" is the one action among the following actions given in the question that would be the most effective long-term solution to fighting desertification in the Sahel.
This is a personal question, which means that only you can answer it. However, I can give some examples that might help guide your work.
An example of a primary source that you might encounter in your own life is that of a news article. As this article is likely to be written by a reporter witnessing the events, it can be considered a primary source. On the other hand, an example of a secondary source would be a non-fiction book that talks about a historical event. This is because such a book would give a second-hand account of an event based on historical information.
What’s the question then ????