Scientific Instruments
http://www.glencoe.com/sites/colorado/student/science/assets/microscopy.html
http://my.hrw.com/sh/hlc/0030358310/student/ch01/sec03/qc01/hlc01_03_q01fs.htm
http://my.hrw.com/sh/hlc/0030358310/student/ch01/sec03/qc02/hlc01_03_q02fs.htm
http://my.hrw.com/sh/hlc/0030358310/student/ch01/sec03/qc03/hlc01_03_q03fs.htm
http://my.hrw.com/sh/hlc/0030358310/student/ch01/sec03/qc04/hlc01_03_q04fs.htm
http://my.hrw.com/sh/hlc/0030358310/student/ch01/sec03/qc05/hlc01_03_q05fs.htm