An estimate of about 20 feet long
Answer: Option(b) is correct
Explanation:
Positive economics is the field where economy is studied and analysed without predicting about its judgement in terms of goodness or badness. This theory defines about cause and effect that causes economic processes and behavior.
Other options are incorrect because operation of federal government and price level is not set by positive economics also does not describe value decisions and expectation about economy should operate. Thus, the correct option is option(b) .
Answer:
When you want to take a photograph with a film camera, you have to press a button. This operates a mechanism called the shutter, which makes a hole (the aperture) open briefly at the front of the camera, allowing light to enter through the lens (a thick piece of glass or plastic mounted on the front).
Explanation: