presence of mind
noun [ U ] approving uk/ˌprez.əns əv ˈmaɪnd/ us/ˌprez.əns əv ˈmaɪnd/
C2 镇定自若，处变不惊
the ability to make good decisions and to act quickly and calmly in a difficult situation or an emergency
When the gunmen came into the bank, she had the presence of mind to press the alarm. 持枪歹徒闯进银行时，她沉着冷静地按下了警报器。