三叶虫是一种（），在地球上生活了（）年。
A.节肢动物，2.3亿
B.腕足动物，2.3亿
C.节肢动物，3.2亿
D.腕足动物，3.2亿
参考答案：C
Had I known about this computer program, a huge amount of time and energy ________.[ ]
A. would have been saved
B. had been saved
C. will be saved
D. was saved
额定转矩
