in a placid mood
心平气和 placidity

be excitable [placid] by temperament
性情易激动[冷静]

The child had a placid disposition
这个孩子性情温和。

Switzerland is much too placid for my taste
瑞士太宁静了,不适合我的口味。

Immediately after, he becomes engaged to a friend of Elizabeth's, the placid, unimaginative
紧接着他就和伊丽莎白的女友夏绿蒂·卢卡斯订了婚，她性情温和而头脑缺乏想象力。