镇定自若

例句：

1. 1.The tranquil countryside is a welcome respite from the city's hustle and bustle.
   宁静的乡村是城市喧嚣的一片宁静之地。
2. 2.The tranquil atmosphere made it easy for her to concentrate on her work.
   宁静的氛围使她能够专注于工作。
3. 3. The tranquil waters of the lake reflect the clear blue sky above.
   湖面宁静的水映衬着上方清澈的蓝天。