清洗要素：时间：水冲300s碱溶液（）s；水冲300s酸溶液（）s水冲600s。（） A: 1600；1800 B: 1800；1400 C: 1400；1200 D: 1800；1200

The Town Hall _________ in the 1800’s was the most distinguished building at that time.

清洗（单碱洗）流程中：水冲（）碱洗（）水冲（）。 A: 300s、1800s、600s B: 300s、1800s、300s C: 300s、2400s、600s D: 300s、2400s、300s

What did the Irish use to carve the Jack-O’-Lanterns before the 1800’s?

中国大学MOOC: In the early 1800’s America was an increasingly industrious, mercantile, and profit-driven culture. The cultural emphasis on ______ was ever-present.

中国大学MOOC: Question 13 is based on the passage of question 11.Why does the author mention slavery from the 1300s until the 1800s?

2.5G（SDH）设备最多能接入（）个2Mbt/S信号。 A: 1000 B: 1008 C: 1800 D: 2000

LTC1815表示( )。 A: 宽1500,高1500 B: 高1800,宽1500 C: 高1800,宽1800 D: 宽1800,高1500

在桥式（文氏桥）RC正弦波振荡电路中（）。 A: φA=-1800，φF=+1800 B: φA=+1800，φF=+1800 C: φA=00，φF=00

The Town Hall in the 1800’s was the most distinguished building at that time. A: to be completed B: having been completed C: completed D: being completed