All of them try to use the power of the workstation ______ information in a more effective way.

单项选择题We（）on this project for four hours. Let's have a rest.

A. are working
B. have been working
C. worked
D. had worked

单项选择题Galileo lived in the City of Pisa, ______ there is a leaning tower about 180 feet ______.