天文学家能够测定每颗恒星的亮度。An astronomer can determine the brightness of each star.星星的光亮度各不相同.Stars vary in brightness.用18瓦的荧光灯灯泡有同样的亮度，而用电量却减少75％。With an 18-watt fluorescent bulb you get as much light but use 75% less electricity....
鲦鱼仍然不省人事,他在水中漂浮了一会儿.Still stunned, the fish floated about for an instant.当实验者将玻璃抽去后鲮鱼也不再尝试去吃鲦鱼.After laboratory technician glass draw off , the dace fish also no longer attempts eats the dace....
See how many cups and saucers we have - but don't count in the cracked ones.看我们有多少个杯碟― ― 可是不要把破裂的算在内.everyday objects such as cups and saucers诸如杯碟之类的日用品He placed cups and saucers on the table.他把杯子和茶碟放到桌上.... a boxed...