Afigure is a parallelogram if, and only if, it is a quadrilateral and has exactly two pairs of parallel sides.
(a "quadrilateral" is a four sided figure )
a] a figure is a parallelogram, therefore the figure is a rectangle
b] a quadrilateral has exactly two pairs of parallel sides therefore it is a parallelogram
c] a figure has two pairs of parallel sides therefore it is a parallelogram
d] a parallelogram is not a quadrilateral unless it has two pairs of parallel sides

“i didn't know that cheshire cats always grinned; in fact, i didn't know that cats could grin.” “they all can,” said the duchess; “and most of 'em do.” “i don't know of any that do,” alice said very politely, feeling quite to have got into a conversation. “you don't know much,” said the duchess; “and that's a fact.” what is the effect of the short sentences on the dialogue? they make the dialogue smooth and serene. they make the dialogue lively and humorous. they make the dialogue formal and elegant. they make the dialogue into a song.

What do both in memoriam, a. h. h. and “the lady of shalott” by alfred, lord tennyson suggest about people’s relationships with others? people can remain united even in death. people are mysterious and can never fully know one another. separation from others can lead to pain and loneliness. people create barriers that can prevent them from forging ties with others.

Analysis that compares and contrasts the way two myths show one important feature of their culture