You can use a plotting compass or iron filings to detect a magnetic field:
1.put a piece of paper over a magnet (this stops the iron filings sticking to the magnet)
2. sprinkle iron filings onto the paper
3.gently tap the paper to spread the filings out
4.observe and record the results
I believe that these are ABIOTIC factors since they are not living.
Only the strongest live on to pass on their genes. the weak die
Alfred Marshal was one of the most influential economists of his time and the author of the Principles of Economics book which was the principal economic textbook in England for long years. During his economic theory development, he borrowed a concept from the marginalists which is the theory of demand and the collective result of buyers who yearns services and products or the concept of scarcity.
The answer is B, bird flu. The other diseases have been around much longer than bird flu has. Bird flu has been in Asia since 2003, but didn't reach Europe and the middle east until 2005, making bird flu a very new disease.
