A：until; which
B：when; that
C：before; that
D：as; which
—I spent two weeks in London last summer.
—Then you must have visited the British Museum during your stay, ________ you?
已知液态的二氧化碳、氧和氮在标准大气压下的沸点分别是﹣78℃、﹣183℃和﹣196℃．如果在标准大气压下用降温的方法从空气中提取这些物质，则首先液化而分离出来的是（ ）
①切碎____ ②给……带来好运____ ③喂鸡____
④相当多____ ⑤在农村____ ⑥消防站____
⑦总的来说____ ⑧对……感兴趣____
⑨深夜不睡____ ⑩跑开____
神经中枢分布在脑和脊髓的灰质中．
