1. When the unthoughtful child called his mom names his mom just kept quiet, heart in tears.2. When you brought your obnoxious boyfriend to dinner we had to put up with him in silence.
 keep quiet suffer in silence< >
這是一個連環問題: 燃燒石油導致二氧化碳增加，二氧化碳增加導致溫室效應，溫室效應導致冰層融化、海平面上升。 (請填空)
This is a chain of problems. Burning oil leads to increase in carbon dioxide, which leads to the greenhouse effect, which leads to melting of glaciers, which leads to rising sea evels.