Laboratory tests of newer electric velomobiles seemed promising: redesigned motors consumed about 20 percent less energy than earlier motors did. Yet road tests found only a small increase in range because larger cabins and added equipment required nearly, but not quite, the same amount of energy that the motors saved. In practical use, then, the added weight ______ the motors’ efficiency gains.
Which choice completes the text with the most logical and precise word or phrase?
For a Words-in-Context question, identify the exact relationship established by the surrounding details before comparing the choices. When several options share a broad meaning, use distinctions involving cause, degree, and scope—for example, whether an effect was hidden, generally reduced, fully canceled, or precisely counterbalanced—to select the most accurate word.
Hints
Track both effects
Identify what the redesigned motors did to energy use and what the added weight did to energy use. The effects work in opposite directions.
Distinguish result from visibility
The passage explains that the added weight actually changed the practical result, not merely how noticeable the motors’ improvement was.
Attend to degree
The phrases “only a small increase” and “nearly, but not quite” show that most of the benefit was counteracted, but some benefit remained.
Step-by-step Explanation
Identify the two opposing effects
The redesigned motors reduced energy consumption, which should have increased the vehicles’ range. However, the larger cabins and additional equipment increased the energy needed to move the vehicles.
Use the quantitative relationship
The added equipment required nearly, but not quite, the same amount of energy that the motors saved. Thus, one effect counteracted most of the other effect, although a small net improvement remained.
Choose the most precise word
To offset something is to counterbalance or counteract it. This word precisely describes how the energy cost of the added weight opposed most of the motors’ efficiency gains without eliminating them completely.