1.It has taken many years to adopt internationally recognized standards for the licensing of aircraft pilots.
(A) data (B) criteria (C) committees
2.No form of money has ever proved completely satisfactory in terms of providing a stable measure of value.
(A) an official (B)a useful (C)a fixed
3.The Rio Grande, a river bordering Texas and Mexico, flows 1,800 miles from its source in the state of Colorado to the Gulf of Mexico.
(A) bank (B) mouth (C) beginning
4.Most animal fats are saturated, containing more hydrogen than carbon, and do not spoil as easily as unsaturated fats.
(A) melt (B) get used up (C) go bad
5.The boom in silver production after 1860 spurred the use of innovative machinery in crafting silver flatware and vessels
(A) stimulated (B) allowed (C) required
6.Ravaged by pollution and war, many famous monuments have become eroded and stained.
(A) discolored (B) dismembered (C) discredited
7.Before the first Apollo rocket went to the Moon, a spot for landing the lunar module(登月舱) was carefully chosen.
(A)climate (B)latitude (C)location
