>1. Xerox has relied on the credit facility _____ its credit ratings were cut to junk status just a year ago. >a. before b. while c. when d. since >>답은 D번. 우선 주어+동사 가 2개씩 있으므로 접속사가 들어와야 하겠구요>종속절의 시제를 보니 현재완료가 왔네요. 그러므로 since가 와야 겠지요>>2. That must have seemed a great idea when the stock price ______ soaring. >a. has been b. were c. had been d. was >>a번 같은데요. 시제일치해야 되므로 둘다 현재 완료 >>3. The two items which all groups related as the most important were high-quality leadership and healthcare _____. >a. benefits b. beneficial c. beneficent d. benefit >>명사 and 명사로 병치구조가 되어야 겠네요. 그럼 A번의 benefits가 와야겠지요.>>4. There are worrying signs that regulations are becoming more intrusive in _____ areas as financial services, water and electricity. >a. so b. some c. such d. since >>답은 C 같구요. As 뒤에 열거된 지역들 처럼 몇몇 지역들이란 뜻을 가진.>Such areas as~게 되야 할거 같아요> >>>

님의  답에 다 동의하겠는 데  한가지는  must have been을  must 의 과거형으로 볼 수 있지 않을 가요?   그래서  답은

the stock price 'was'로    was일 것 같은 데 어떻습니까.