although 也对。参考
https://tinyurl.com/ybkwvl22 英文语言/文法书籍
https://tinyurl.com/y8kxb5hq The New York Times 的例although 是有这样子的用法:
https://tinyurl.com/y8tndlwp ->Usage Note 找When though introduces only .....但是原题目句子的"not"是代前头整句(的否定):not: [new one are coming in]否定 ->{(new ones are) not (coming in)} {as quickly as ..}这跟Usage Note里头提到的"introduces only a part of aclause"不一样题目原句子出自 Costco 的刊物(是用 but)。但是出题人没注意到 although 也是正确用字