WITH WHAT TOPIC IS THE PASSAGE PRIMARILY CONVERNED

14. - DE THI THU DH THAN KHAO CO DAP AN
Tiếng Anh DE THI THU DH THAN KHAO CO DAP AN
14. With what topic is the passage primarily converned?A. Communication among drivers. B. Technological advances in oceanography. C. Undersea vehicles. D. Direct observation of the ocean floor.