This means that our noses are limited to perceiving those smells which float through the air, ( ) the majority of smells which stick to surfaces. 括号处选项有 catching 、missing问题一：如果把括号前面的逗号变为and，则[ ]处和前面的perceiving并列 则按句意填catching问题二：就是因为有了逗号，括号引导的的现在分词短语才在前面的宾从中作结果状语或伴随状语，此时填missing。问题三：一个复合句，两个部分并列一般得用连词链接。如果是逗号，说明逗号前...
