句子使用了What引导的主语从句，is作为系动词连接表语，结构清晰，强调行动的重要性。
In life, there are inevitably gains and losses, joys and sorrows. These events are often beyond our full control and cannot be precisely predicted; they frequently arrive unexpectedly. What we can do is respond proactively and adjust our state accordingly.
When joy arrives, we must strive to maintain composure, avoiding arrogance or excessive pride born from happiness. When sorrow strikes, we must exert effort to restrain our emotions, preventing ourselves from losing our sense of self or falling into endless anguish. We should face all aspects of life—whether gains or losses, joys or sorrows—with equanimity. If something is gained, there is no need to deny it; if something is lost, there is no need to avoid it. Only by remaining calm can we handle the gifts and challenges of life with grace and composure.
人生之中，难免会有得与失，也会有悲与喜。这些际遇往往难以掌控，也无法预先判断，常常在不期而至中突然降临。面对这一切，我们能做的便是积极应对，适时调整自己的状态。
当喜悦来临，我们要尽力控制自己，不因快乐而变得张扬狂妄；当悲伤袭来，我们要竭力克制情绪，不因痛苦而迷失自我、陷入无尽的哀伤。对于人生中的种种境遇，无论得失还是悲喜，我们都应当坦然面对。得到了，不必刻意否认；失去了，也不必刻意回避。唯有保持冷静，才能从容处理生活的每一份馈赠与考验。