What are some of the medical advances made recently? MRIS
Camera's small enough to swallow
Sterilization of instruments
Eye glasses
Penicillin
CAT scans

An easy way to calculate the amount of energy available at each level is to what?

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

In which part of the body is a ball-and-socket joint found?