The iob format categorizes tagged tokens as i, o and b. why are three tags necessary? what problem would be caused if we used i and o tags exclusively?

Explain briefly why you cannot expect to find a previous version of every file with which you work.

Verify each identity[tex] \frac{csc}{cot \: x \: + \: tan \: x} = cos \: x[/tex]

Adrawing that places all lines parallel to the z axis at an angle from the horizon is 99 ! a. an oblique drawing b. a perspective drawing c. an auxiliary view d. a one-point perspective drawing