Moving toward the Southern border of the United States, English becomes less common and Spanish is more often spoken. What type of region does this gradual change of language reflect?

Which of the following is not part of dust?

A) mineral particles B) water molecules C) pollen and spores D) microbes

Your car lights were left on while you were shopping, and now your car battery is dead. Has the pH of the battery fluid increased or decreased?

A. The pH of the battery fluid has increased. B. The pH of the battery fluid does not change. C. The pH of the battery fluid has decreased. D. Since the lights were left on and the battery is dead, the pH of the battery fluid must be zero.

The term for the two days of the year when the circle of illumination crosses the equator at right angles to provide 12 hours of daylight at every spot on the globe is _______________

Fill in the blank(s) with correct word

Two species of frogs do not interbreed because one species breeds in March and the other species breeds in May. This is an example of

A) allopatric speciation. B) sympatric speciation. C) a prezygotic reproductive barrier. D) a postzygotic reproductive barrier.