阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
A
“Were the birds on the ice ducks or geese？” Cruz Genet, 11, and Anthony Skopick, 10, couldn't agree. There was only one way to find out. So on a cold January evening, the two friends risked onto the frozen pond near their houses in Frankfort, Illinois, to get a better look. First they threw a small stone to test it. Then they stepped on it. Believing the ice would hold their weight, Anthony took a few steps, then… He fell through the seemingly frozen ice.
Cruz rushed to help his frightened friend—the pond “ate” him too. Cruz managed to lift himself out of the water and onto a more reliable part. He then carefully made his way to Anthony. But the ice didn't hold, and he fell in again. This time he couldn't get out. The boys quickly lost feelings in their arms and legs. Cruz was sure he was going to die.
Anthony's older sister had seen the boys fall through the ice and started screaming for help. John Lavin, a neighbor driving nearby on his way to the grocery store, heard her. He quickly pulled over. Seeing the boys, he kicked off his shoes, and ran into the freezing water. Lavin made his way to Cruz and Anthony and saved them back to land. They were taken to the hospital, where doctors discovered that their five－minute stay in the water had lowered their body temperature nearly ten degrees.
Fortunately, the boys have fully recovered, though they are still moved by their fearless neighbor. “Just to think，” says Cruz，“if he wasn't there, I could have died.”
21．Why did Cruz and Anthony step on the ice?
A．To go skating. B．To trap some birds.
C．To settle a disagreement. D．To test the strength of the ice.
22. How did Cruz feel when caught in the water?
A．Hopeless. B．Puzzled. C．Shocked. D．Calm.
23.What basically（从根本上说） saved the two boys' lives?
A．Screaming of an older sister. B．Better care from doctors.
C．Lowering of their body temperature. D．Brave act of a neighbor.
