GRE填空练习题3（附答案）(2)

　　【16】That the President manages the economy is an assumption (i)______________ the prevailing wisdom that dominates electoral politics in the United States. As a result, presidential elections have become referenda on the business cycle, whose fortuitous turnings are (ii)______________ the President. Presidents are properly accountable for their executive and legislative performance, and certainly their actions may have profound effects on the economy. But these effects are (iii)______________. Unfortunately, modern political campaigns are fought on the untenable premise that Presidents can deliberately produce precise economic results.

　　【17】Room acoustics design criteria are determined according to the room’s intended use. Music, for example, is best (i)______________ in spaces that are reverberant, a condition that generally makes speech less (ii)________________. Acoustics suitable for both speech and music can sometimes be created in the same space, although the result is never perfect, each having to be (iii)_______________ to some extent.

　　【18】To the untutored eye the tightly forested Ardennes hills around Sedan look quite (i)_______________， (ii)________________place through which to advance a modern army; even with today’s more numerous and better roads and bridges, the woods and the river Meuse form a significant (iii)_______________.