A.I. Explanation:

Correct Answer: SideFlow

Why this is correct: The SideFlow has a hose outlet on the left, fits flat against a wall and restarts on its last setting. Its night mode is 44 dB, which is within the 45 dB rule in the footer. The blank sits in the Subject line, because this is the model Casey asks Ms. Green to approve.

Tips: For a choice between several models, cross out each one that breaks one rule. The model left standing is the answer.

Why the other options are wrong:

• BasicDry: The BasicDry needs 20 cm of space behind it, and the spot has a pipe right against the wall.
• QuietDry: The QuietDry can only use a tank, and nobody will be home to empty it on weekends.
• MaxDry: The MaxDry is 48 dB in night mode, which breaks the 45 dB rule for rental suites. It also must be restarted by hand.

Correct Answer: 20 cm of clear space behind it

Why this is correct: The BasicDry row says it needs 20 cm of clear space behind the unit. Casey says a fixed pipe runs along the wall, so the unit must sit tight against it. That is why the BasicDry does not fit.

Tips: Read the email for the problem with the space, then find the row detail that clashes with it.

Why the other options are wrong:

• a hose outlet on its left side: The BasicDry's hose outlet is at the back, not on the left side. A left outlet belongs to the SideFlow and the MaxDry.
• its tank emptied every morning: The BasicDry can drain through a hose all the time, so its tank does not need emptying every morning.
• someone to restart it by hand: The BasicDry restarts by itself in default mode. Only the MaxDry must be switched on by hand.

Correct Answer: can only drain into a tank that must be emptied

Why this is correct: The QuietDry has a tank drain only and no hose outlet, and it stops when the tank is full. Casey is away on weekends, so nobody can empty it.

Tips: Two problems can sound right in the sentence. Check which one the diagram gives for this exact model.

Why the other options are wrong:

• must be switched on by hand after a power cut: The QuietDry restarts on its last setting. Switching on by hand is a problem with the MaxDry.
• is too loud for a bedroom in night mode: The QuietDry is the quietest model at 38 dB, well within the 45 dB rule.
• needs 20 cm of clear space behind the unit: The QuietDry fits flat against a wall. The 20 cm of space is needed by the BasicDry.

Correct Answer: start again on its last setting

Why this is correct: The SideFlow row says it restarts on its last setting after a power cut. So if the power goes out while Casey is away, it will start again by itself.

Tips: Once you know the chosen model, answer every later blank from that same row.

Why the other options are wrong:

• wait until someone switches it on: Waiting for someone to switch it on is the MaxDry rule, not the rule for the model Casey chose.
• restart in its default mode: Restarting in default mode is how the BasicDry works. The SideFlow keeps its last setting.
• keep running on battery power: No model in the guide has a battery, so none of them keeps running in a power cut.

Correct Answer: a little louder but able to drain through a hose

Why this is correct: The SideFlow is 44 dB at night and the QuietDry is 38 dB, so the chosen model is louder. But it can drain through a hose, which the QuietDry cannot do.

Tips: When two things are compared, check both halves of the answer. One true half is not enough.

Why the other options are wrong:

• quieter and also able to drain through a hose: The SideFlow is not quieter. It is 44 dB, while the QuietDry is 38 dB.
• a little louder and limited to a small tank: The SideFlow is louder, but it is not limited to a tank. It can drain through a hose all the time.
• just as quiet but able to cover a larger room: The SideFlow is not as quiet, and it covers a smaller room than the QuietDry.

Correct Answer: ask for approval of a model and a way to drain it

Why this is correct: Casey explains the chosen model and says the hose will go into the existing floor drain. Casey then asks Ms. Green to confirm the plan before placing the order.

Tips: The request near the end of an email usually shows the main purpose.

Why the other options are wrong:

• ask Ms. Green to empty the tank on weekends: Casey chose a hose model so that nobody has to empty a tank. Ms. Green is not asked to do this.
• report that the basement water pipe is leaking: Casey mentions the pipe only because it limits the space. Nothing says it is leaking.
• ask for permission to drill a new drain hole: Casey says the hose will use the existing drain without any drilling.

Correct Answer: It can drain through a hose while nobody is home.

Why this is correct: Casey says a full tank would stop the machine for the whole weekend. The chosen model can drain through a hose, but the quietest model, the QuietDry, can only use a tank.

Tips: Find the sentence where the writer explains a trade. The reason is usually right there.

Why the other options are wrong:

• The quietest model covers too small a room.: The QuietDry covers 60 square metres, more than the model Casey chose.
• The quietest model has its hose on the wrong side.: The QuietDry has no hose outlet at all, so its hose cannot be on the wrong side.
• The quietest model does not restart after a power cut.: The QuietDry restarts on its last setting, just like the chosen model.

Correct Answer: careful and respectful of the rules

Why this is correct: Casey checks all four models against the rental rules and plans to use the existing drain without any drilling. Casey also asks for approval before ordering, which shows respect for the rules.

Tips: For tone, look at what the writer does as well as the words they use.

Why the other options are wrong:

• hurried and careless: Casey is not rushing. Casey checked all four models against the rules before choosing one.
• doubtful and discouraged: Casey is confident about the choice and has a clear plan.
• annoyed and demanding: Casey writes politely and asks for approval instead of making demands.