Question 19 What is an advantage of a nuclear-fission reactor?
А
The nuclear waste generated has a very long half-life.
B
The products of fission reactions are often radioactive isotopes.
С
The power plants are only expensive if they require radiation shielding.
D
A large amount of energy can be produced from a small amount of uranium.

The study of interaction between living organisms and their enviroment is called (a) phytogeography (b) ecology (c) phytosociology (d) ecosystem

An ecologist is studying the effects that a population of predators is having on a population of a prey. he used data from the field to produce this graph. which conclusion can draw from the graph?

Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. scientists played sounds they had identified as the names of particular dolphins, putting them through a synthesizer so that they did not sound like the voices of particular dolphins. the researchers found that dolphins would respond to the names of other dolphins that they were related to or associated with, but they ignored the names of strangers. this discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. if this research holds up, what does it suggest about dolphins?