Questions

Getting the value of an environment variable is done by using `getenv()’. Setting the value of an environment variable is done by using `putenv()’

Mass means the amount of matter in an object. Anything that has Mass and takes up Space is called Matter.

The Study of Matter and and how matter changes is called Chemistry.

Matter has some mass and occupies some space. Space occupied by an object is called its Volume.

Evaporation is the process that allows water to enter into the atmosphere.

Sunlight turns liquid water into water vapor which then rises higher into the atmosphere and forms into clouds.

Plants, too, help water get into the atmosphere through a process called transpiration.

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.