单项选择题
The passage implies that the telegraph cable was built mainly ()
A. for investigating the depths of the oceans B. for military purposes C. for business considerations D. for oceanographic studies
单项选择题 "Defied" in the 5th paragraph probably means ()
单项选择题 According to the author, in order to stay young and attractive, women should ()
单项选择题 Laser-doppler radar ()
