To explain this, they hypothesise that galaxies must contain a great deal of missing matter which cannot be detected. 为了解释这一点，他们假定各星系一定包含了大量无法探测到的不明物质。
配偶之间政治观点上的相似度要大于他们身高的相似程度。The political opinions of spouses correlate more closely than their heights.大多数女性都比配偶长寿。Most women will survive their spouses.雄性动物死死地守护着他们的配偶。The males guard their mates zealously....