The Cheshire cat caused the Queen of hearts to fall over
The answer is "PET scan" or "PET-CT".
PET scan or positron emission tomography uses the technology behind conventional CT scans but performs to quantify the function in specific parts of organs (i.e. brain). The patient will be given a positron emitting substance most commonly fluorodeoxyglucose or FDG via intravenous injection. After which, the patient will go to the PET machine and the PET machine will measure the positron emitted throughout the body. Positron is well correlated to the function of a specific part of an organ.
Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
True millions of different species live on coral reefs
Hydrogen fuel cell powered cars emit a 0 emission.
