Is the use of sound waves to detect and measure objects underwater.

a. gps
b. gis
c. ostm
d. sonar

Which of the following statements is true? 1. the mantle of the earth is made of solid nickel and iron. 2. the crust of the earth is made of solid nickel and iron. 3. the inner core is made of solid nickel and iron.

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?

Describe how a student should adjust the microscope to see the cells on a slide more clearly?