1. Fluctuations of aggregate economic activity. 2.Cycles Expansion/Boom and Contraction/Recession. Peak and Trough: They are the turning Points of the business cycle. 3. Comovements of many macro variables over the business cycle.
Section 5: Using external media: CDs, DVDs and removable USB storage devices. â¢ dvd-r:until about 2005 the most common and portable format; cannot be erased or reused. â¢ dvd-rw:are-writable version of-rformat, similar to cdrw format CD discs.
Some drives can only read from certain discs, but recent drives can both read and record, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives. Optical disc drives that are no longer in production include CD-ROM drive, CD writer drive, and combo (CD-RW/DVD-ROM) drive.