Self-study
In deep temperate lakes, water temperatures vary according to depth. ██ ███████ ███ ███████ █████ ██ ██ ███ ████ ██ ███████ ██ ███ ███████ ███ ███████ ██ ███████████ █████████████ ██ ███████████ █████ ██ ████ ███ ████ ███████ ████ █████ ████ ██ ██████ ██ █ █████ ██ ███ ███████ ██████ ███ ██ ███████ ████ ████ █████ ██ ████ █████████ █████ █████ █████ █████ ███ █████████ ████ ████ ██ ████ ███████ ████ ████ ██ ████ ██ ██████ ███ ████ ███████ ██████ ██████ ███ ████ ███████ ██ █ ███████ ███ ██ █████ ██ ███ ███████ ███ █ █████ ██████
Summary
If anglers want to find lake trout in a particular kind of lake while this lake is partially iced in late winter, then they should fish near the surface. Why? Because:
1) Lake trout will be in the coldest water.
2) This particular kind of lake undergoes temperature changes in late winter and fall; during this time, the location of the coldest water will change.
3) In winter, the coldest water is at the top.
Notable Assumptions
The recommendation specifically speaks to anglers fishing during late winter, which is when the turnover happens. We don’t know when exactly this turnover occurs, we only know it’s sometime in late winter. So, we don’t know whether the anglers are fishing before or after the turnover. If it’s before the turnover, then yes, the coldest water will be on top. If it’s after the turnover, then the coldest water will not be on top. We need to know that the turnover hasn’t happened yet.
17.
Which one of the following ██ ██ ██████████ ██ █████ ███ ████████ ████████
a
The ease with █████ ████ █████ ███ ██ ██████ ██ ███████ ██████ ████ ███ ████ ██ ████ ███ ███ █████ ████████████
We can’t make assumptions about what (A) is saying. (A) says the difficulty level changes—okay, but in what way? We don’t know, and we can’t assume. We’ve been told that the location of trout changes with timing/water temperature, but that doesn’t make one option easier than the other.
b
Cold water is ███████ ███ █████████ ████████ ████ ██████████ ██████ ██████
Comparing density and heaviness of water doesn’t matter. We are discussing where to find the lake trout, and using the information we were given to try and do that.
c
Lake trout are █████ ███████████ ██ ████ █████████ ██████
The conclusion is specific to anglers that are looking for lake trout in deep temperate lakes. It doesn’t matter if they can be found elsewhere.
d
Lake trout do ███ █████ █████ ███████ ██████ ████ ███ ████ ██ ███ ████ ██ ████████
It doesn’t matter if they do. We were told that, as a rule, lake trout will be found in the coldest water.
And, even if they do alter their feeding habits, we don’t have any information on that variation.
e
In deep temperate █████ ████ ████ ███ ████████ ██ ███ ████████ ███████████ ██████████ ███ ███ ███ █████████
This must be true. If (E) is not true, and turnover has occurred, then the lake trout will not be found at the surface level; the argument would be ruined.