With most online recruitment services, jobseekers must choose their words carefully;________the search engine will never make the correct match.
句子前面提到“通过网上招聘找工作的人必须小心用词”, 空白处后面提到“搜寻器不会做出正确的配对”, 那么根据上下文, 应该选择 otherwise, 意思是“否则就……”。类似例句还有: We were delayed at the airport. Otherwise we would have been here by lunch time. (我们在机场耽搁了, 不然的话, 我们在午饭前就到这里了。 )They got two free tickets to Canada, otherwise they'd never have been able to afford to go. (他们得到了两张免费去加拿大的机票, 否则他们永远支付不起去那里的费用。 )therefore 表示结果; whereas 表示转折, 意为“而……却……”; provided 意为“假如……” 或“以: …—为条件”。