Self-study
Some plants have extremely sensitive biological thermometers. ███ ████████ ███ ██████ ██ █████████████ ████ ████ ███ ███████████ ██ ███ ███ ██████ ████ ██ █████ ████ ██████████ ██████████ ██████ ██████ ████████ ████ ██ ████████████ █████ █████ ██ ███████ ███ ██████████████ ████████ █████████████ ████ ████████ ███████ ████████ ████ ██████ ███ ████████ █████████ ███ █ ███████████ ███████ ████ █████ █████████ ████ ███ █████████████ ███████ ███ ████████ ██ ██████ ████ ██ █████ █████
Summarize Argument
The author concludes that someone observing two separate plant phenomena while a thermometer displayed 1°C would be able to determine that a thermometer reading is correct to within plus or minus 1°C. This is because rhododendrons curl when the air around them is below 0°C, while mature crocus blossoms open when the air around them is above 2°C.
Notable Assumptions
The author assumes that air temperatures are consistent in the observed area. Since crocuses open above 2°C, the temperature around the crocuses has to be below 2°C to see closed buds. But the rhododendrons would remain uncurled at any temperature above 0°C, which means the air around them could be warmer than 2°C.
15.
Which one of the following, ██ █████ ████ █████████ ██████████ ███ █████████ ██████
a
Neither rhododendrons nor ████████ █████ ███ ████ ████ █ ███ █████ ████ █████ ███ ███ ████████ ██ █████████████ ███████ ██ ███ ████ ██ ███ ██████ █████ ██ █████ ███████ █████ █████ ████████ ███████ ██ ████ ████ ████ ██████ ██ ██████
We care about rhododendron leaves, not about their blossoms, so this isn't relevant to the argument.
b
Many people find ██ ██████████ ██ ██ ████████ ███ ████ ███████ ████ ███ ███████████ ██ ██ ██ █████ █████
Unfortunately for them, we don’t care about the people holding the thermometer. We’re only interested in whether rhododendron leaves and crocus blossoms can tell us about the thermometer's accuracy.
c
The climate and ████ ██████████ ████ █████ ███ ██████ ██ █████████████ ███ ████ █████████ ██ ███ ██████ ██ █████████
It doesn’t matter how these plants grew, because the argument requires them to already be present. We care about a specific instance of using the plants’ biological thermometers to test a mechanical thermometer.
d
Air temperature surrounding ██████████████ █████ ███ ████ ██ ████ █████ ██ ██████ ██ ██████ ████ ███ ███████████ ███████████ █████████ █████ ███ ████████ ████ █ ███ ██████ █████ ██ ████ ████ █████ ████ ██ ███ ███ ██████ ███ ███████ ████ ██ █████
Since the air temperature surrounding the two plants is likely to differ, we can’t use the plants’ reactions to temperature to gauge if the thermometer reading is right. The plants might be reacting to different temperatures. This weakens the argument.
e
Certain types of ████████████ ████ ███ ████████ ████ ██ ███████ ███████ ████████████ ███ ██ █████████ ████████ ██ ████████ ███████████ ██████ ███ ████ ████ ████████ ██ ██████ ██ ██████ ███████████ ███████
We don’t know what a “moderate” temperature is. 0°C? 20°C? Besides, the accuracy of the thermometer has no bearing on the argument. The conclusion is all using plants to test the accuracy of a thermometer.