to change your opinion or attitude
改变你的意见或态度
"He criticized the plan at first but later changed his tune."
"一开始他批评了这个计划，但后来他改变了看法。"
a period of difficulty or trouble
smiling broadly due to happiness
to remove tension or misunderstanding by talking openly
someone who is emotionally strong and unyielding
to work hard on something for a long period
a significant discovery or achievement in science or researc...
