Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Glaciers are melting, sea levels are rising, and cloud forests are dying. More alarmingly, wildlife is scrambling to keep (23) ____. It's becoming clear that humans have caused most of the past century's warming by (24) ____ heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.

We call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. As the Earth spins each day, the new heat swirls with it, (25) ____ up moisture over the oceans, rising here, settling there. It's changing the rhythms of climate that all living things have come to rely upon.

What will we do to slow this warming? How will we cope (26) ____ the changes we've already set into (27) ____? While we struggle to figure it all out, the face of the Earth as we know it-coasts, forests, farms and snow-capped mountains-hangs in the balance.