println(a - b); // 7.0
There aren’t many settings to adjust on an air purifier. Most have low, medium and high fan speeds and possibly an auto-mode that detects impurities in the air and increases the fan speed on your behalf. Air circulates through a purifier faster at higher fan-speed settings so it cleans the air more efficiently. Higher speeds also make the air purifier louder. That means you typically want to find the balance between cleaning power and noise levels.
。关于这个话题，新收录的资料提供了深入分析
"We recognise that energy costs remain a concern for customers across Northern Ireland," he said.，推荐阅读新收录的资料获取更多信息
DigitalPrintPrint + Digital
Никита Хромин (ночной линейный редактор)