At each step, the programmer is able to see if, and how, a variable is affected. Trace tables are extremely useful because they enable a programmer to compare what the value of each variable should be ...
Late 1600s – Dutch scientist Antonie van Leeuwenhoek constructed a microscope with a single spherical lens. It magnified up to ×275. 1800s - the optical quality of lenses increased and the microscopes ...