1. These heaters are less obtrusive and are easy to store away in the summer. 这些取暖器不那么难看，在夏天也容易收藏。
2. Around the beginning of the 20th century there were actually some primitive solar water heaters on the consumer market. 大约20世纪初，消费市场上出现了一些原始的太阳能热水器。
3. They have evolved special "heaters" of modified muscle tissue that warm the eyes and brain, maintaining peak performance of these critical organs. 它们进化出了一种特殊的“加热器”，由经过改造的肌肉组织构成，可以温暖眼睛和大脑，使这些关键器官保持最佳状态。
4. The heaters have water-filled steel tubes that zigzag in front of a reflective surface, which concentrates the sun's rays on the tubes. 这种加热器装有充满水的钢管，在反射面前头曲折布置，反射面将太阳光聚焦在钢管上。
