【正确答案】 A

【答案解析】[解析] appalling表示条件之差使人感到吃惊。dreadful有类似的意义。如：My financial situation is dreadful．此句改用appalling也是可以的。bad，unpleasant和poor都可以跟condition搭配。因此可以说：They have been living under bad conditions for two years.They have been living under unpleasant conditions for two years．They have been living under poor conditions for two years．注意：appalling conditions蕴涵：bad(或unpleasant或poor)conditions.但反向的蕴涵是不成立的。用句通俗的话说，是appalling conditions必定是bad(或unpleasant或poor)conditions，但是bad(或unpleasant或poor)conditions未必都是appalling conditions。也就是说，appalling跟bad，unpleasant和poor在意义上存在着明显的差别。注意：如果用bad或poor替换appalling，生成的都是错误的句子。