21. In paragraph l, the word "facades" means________.A、the exterior walls of a building
B、the shape ofa building
C、the interior walls ofa building
D、the framework of a building
【正确答案】：A
【题目解析】：词义推断题。facades一词出现的上下文是：Instead of developing surfaces resistant to moss and lichen, the BiotA lab wants to build facades that are "bioreceptive"。由于instead of 通常是关于同一事物的相反或不同操作，resistant /receptive恰恰是一对反义词语，因此推断facades在本句中的同义词应是surfaces（表面）。选项A里面的exterior（外表；外部）与surface为同义词，因此也和facade为同义词，故而A是正确答案。