We are close to a knowledge of annual summer and winter temperature variations over much of the northern hemisphere going back 600 years.
我们很快就会知道，600年前北半球大部分地区每年夏季和冬季的温度是如何变化的。
2
The Moon's brightness varies throughout its annual cycle, during the mid-winter in the northern hemisphere it can appear brighter simply because it is higher in the sky.
月球的亮度随着轨道位置的变化而变化，在北半球的深冬，月亮会更亮，因为它在天空中更高。
3
The annual survey by the British Beekeepers' Association revealed 19.2 per cent of colonies died in the winter.