Why is there one winter and one summer each year?

Which sequence of transformations on preimage ∆abc will not produce the image ∆a'b'c'? a. reflection across the line y = x b. rotation 180° clockwise about the origin followed by a reflection across the line y = -x c. reflection across the x-axis followed by a reflection across the y-axis d. reflection across the line y = -x followed by a rotation 180° counterclockwise about the origin e. reflection across the y-axis followed by a rotation 90° clockwise about the origin

Why is the improved education of girls so important, especially with regard to economics and health? what are the leading causes of death among teenage girls in africa and how are they tied to education?

This word for a bug or malfunction was popularized in the 1962 book into orbit by the mercury astronauts