Tpo24阅读分析(4)

○The residence times of surface-water-dominated lakes are usually longer than those of seepage-dominated lakes. (原文没说，不选)

○The residence time of a lake frequently depends on the kinds of organisms to be found in the lake. (organism是renewal减慢带来的影响，不是residence time的决定因素，不选)

Reading 02 Breathing During Sleep (1)

paragraph4: But that is not all that changes. During all phases of sleep, several chang

efficiency of the muscles used for breathing. Some of the muscles that help keep the upper airway open when breathing tend to become more relaxed during sleep, especially during REM (the phase of sleep in which there is rapid eye movement). Without this muscular action, inhaling is like sucking air out of a balloon—the narrow passages tend to collapse. Also there is a regular cycle of change in resistance between the two sides of the nose. If something blocks the "good" side, such as congestion from allergies or a cold, then resistance increases dramatically. Coupled with these factors is the loss of the complex interactions among the muscles that can change the route of airflow from nose to mouth.

5. What is the author's purpose in stating that inhaling is like sucking air out of a balloon?

○To refute the argument that additional effort is necessary for breathing during sle