A ruler is a tool that allows you to measure.  So we must look at the second part as "wrench is a tool that allows you to _____". The main purpose of a wrench is to tighten or loosen nuts and bolts.  So either tighten or loosen would be correct answers, and tighten is the only word present here.

The sense of this analogy is that as a knife is used for cutting, so a pencil is used for writing. The other options are wrong for a number of reasons. Graphite is what allows the pencil to write, not the act one does with the pencil. The pencil is an instrument, but that doesn’t describe the action. Not even “writer” is appropriate, for that would describe who would use the pencil, not what one does with it. Finally, paper is that upon which you write, not the actually act itself.

Since it is safe to say that the general purpose of a vehicle is to transport things, we can say that the general purpose of a tractor is to haul. Now, you might think of the general uses and location of tractors on agricultural lands and become confused. First, note that the word “tractor” comes from Latin roots meaning “to pull” or “drag.” To “extract” something is to “pull it out.” None of the other words describe an action performed by a tractor. Certainly tractors are used in fields, to haul crops, in agricultural activity, and often have trailers attached. However, none of these words are verbs or directly descriptive of action.

The purpose of a vault is to protect items, so the analogy implies that we need to pick the best description of the purpose of an icebox. The best option here is “chilling,” for that describes the actual thing “done” in or by iceboxes. While they are used to protect food and prevent spoilage, neither of these options describe the actual purpose of the box. Perhaps if the word “preserve” were an option, it would be difficult to choose between chilling and preserving. This is not an issue here, as no other action is offered as a potential answer.

Although both razors and mowers cut things, the analogy can be read as being even more general than, “As a razor cuts hair so a mower cuts . . .” You could also read it as, “As a hair is the proper object of the razor, so too is . . . the proper object for a mower.” While we can use “mower” in a broad sense, the answer options help us to see exactly what is wanted for this question. None of the other options are related to mower in the same manner as hair is related to a razor. While we might store mowers in garages, use them in the summertime, see them in rural places, or run them weekly, none of these options are “acted on” like hair is “acted on” by a razor. For this reason, the simple answer “grass” is the best option.

The best way to describe the relationship between “cloak” and “covering” is that a cloak is used for covering oneself; therefore, the answer needs to describe the use of a trunk. While a trunk can be latched or locked, the only option that describes the actual purpose for a trunk is “storage.” (Recall that a trunk is a type of chest for storage, not merely the rear compartment in a car—thought that could be said to be used for storage as well).

Solder is a type of metal that easily melts; therefore, we could write the bridge sentence for this analogy as, “As solder is a type of metal, so is a treaty a type of X.” A treaty is an agreement, generally between two sovereign nations. Not all agreements are treaties. (A contract, for instance, is a type of agreement); therefore, “agreement” is the best option among those provided, for it alone provides a general class of which a “treaty” is a specific type.

When someone fortifies something, he or she strengthens it against potential attack or assault. The word comes from the Latin for “strong.” A fortification is something that has been strengthened against attack—for instance, a bunker or a castle. It can also refer to the walls and other things used to fortify the given area. Thus, a fortification is used for defense. The analogy could be read as stating, “As a fortification is used for defense, so is telephony used for X.” Telephony is merely “a system using telephones.” This would be used for communication.

A barometer is an instrument for measuring air pressure. When you hear of “barometric pressure,” this is referring to the pressure of the air and often indicates certain aspects of the weather. Now, if you did not know this, you might have been able to guess that we are dealing with something that measures in both cases of our words because they both contain the ending “-meter.” A “chronometer” is something that measures time. The “chronology” of events is the order in which they unfold in time, and “chronic” illness is one that lasts for a long period of time. While a watch and a clock might be chronometers, the analogy wants function, not examples.

The general relationship of this analogy is rather simple, but you need to know the meaning of the word “caching.” A “cache” of something is a hidden set of those items, often stored up for the future. The verb “to cache” merely means “to hide or store for the future.” A cupboard can at least be said to be used for this purpose, even if it has other purposes. For this reason, the analogous word for ladder must describe such functioning. The word “climbing” is best. Think of it this way: “Just as a cupboard can be used for caching, so too can a ladder be used for climbing.”