ir initial trials were highly successful, and ocean acoustic tomography was born. (460 words)

　　1. According to the passage, scientists are able to use ocean acoustic tomography to deduce the properties of the ocean’s interior in part because .

　　[A] density variations in the ocean are mathematically predictable.

　　[B] mesoscale phenomena are so large as to be easily detectable.

　　[C] information from sound waves can be recombined more easily than information from X-rays.

　　[D] low-frequency sound waves are well described mathematically.

　　2. Which of the following is most similar to medical tomography as it is described in the passage?

　　[A] The use of earthquake shock-wave data collected at several different locations and combined to create a three-dimensional image of the Earth’s interior.

　　[B] The use of ocean-current meters to determine the direction and velocity of the ocean’s mesoscale fields.

　　[C] The use of a grid-point sensory system to map global weather patterns.

　　[D] The use of subsurface floats to map large-scale circulation in the ocean.

　　3. Which of the following best describes the organization of the third paragraph of the passage?

　　[A] An argument is advanced, then refuted, and an alternative is suggested.

　　[B] Opposing views are presented, elaborated, and then reconciled.

　　[C] A problem is described, then a solution is discussed and its effectiveness is