strategic management

please help me answer three questions.

No Plagiarize.

just 150 words for each question.

What are the various levels of diversification firms can pursue by using different corporate-level strategies?

What is a restructuring strategy and what are its common forms? Has anyone worked for a company who has had to downsize? If so, why did they downsize?

What are the advantages and disadvantages of single- and dominant-business strategies, compared with those of firms with higher levels of diversification?