How did the sharecropping system work to keep african american from improving their lives

What does the term "deforestation" mean? what landform are we studying that deforestation is impacting greatly in brazil? describe how and why this is happening. plz me!

Awaiver of the requirement for documentation of informed consent may be granted when: the investigator has no convenient place to store signed consent forms separate from the research datathe only record linking the subject and the research is the consent document and the principal risk is a breach of confidentiality.potential subjects might find some of the research questions embarrassing, personal, or intrusivethe subjects are literate in their own language; however, they do not read, write, or speak english

How is the uk’s government is solving the air pollution problem?