1. Scientific investigations of fluid flow behavior around objects like high-speed aircrafts are complex; however, the systems are _______ when experiments are performed in scaled-down versions such as wind tunnels.   turbulent   tractable   malleable   implacable   permeable   Hint Hint       2. The educational system had _______ over a period of time when the authorities got preoccupied with petty politics and did not bother to update the curriculum.   ossified   adulterated   underscored   burnished   relegated   Hint       3. Legislation has been introduced in some states that requires plastic bags be made of biodegradable material which gradually _______ over a period of time when exposed to sunlight.   secretes   subsides   proliferates   ossifies   decomposes   Hint       4. After having _______ arguments virtually every other day, the couple agreed that it was best for them to separate.   saturnine   assiduous   acerbic   effulgent   astringent   Hint       5. It is economically beneficial to increase the capacity of an industrial plant when the revenue can be increased without a _______ increase in the cost of production.   warranted   compliant   precarious   commensurate   controlled   Hint       6. Nature has an apparently _______ source of plants that can be fruitfully exploited for the herbal cure of many diseases.   indefatigable   insatiable   iniquitous   inexhaustible   insuperable   Hint       7. The students appreciated the professor's _______ style of preparing notes for the lectures because the effort in collecting vital information from various sources truly enhanced their learning.   esoteric   pedestrian   dogmatic   eclectic   pedantic   Hint