Questions

A traffic light.

It has three 'eyes' (the red, orange and green lights) and the leg is the pole holding it up. Many people beg the light to stay green as they’re approaching.

Till the stack doesn't overflow

Corn, sugar cane, and sorghum are C4 plants. These plants are economically important in part because of their relatively high photosynthetic efficiencies compared to many other crops.

Acid Precipitation or Acid rain is caused by a mix of Sulfur Dioxide, Carbon Dioxide, Nitrogen Oxides.

A Chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as Acid Rains.

When a function accepts a variable number of arguments , its prototype cannot provide any information about the number of arguments and type of those variable arguments. Hence the compiler cannot warn about the mismatches. The programmer must make sure that arguments match or must manually insert explicit typecast.

A is incorrect. It is acceptable to use assertions to test the arguments of private methods.

B is incorrect. While assertion errors can be caught, Sun discourages you from doing so.

RADAR - RAdio Detection And Ranging.

A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. 

Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.