“turn around and do sth.” 常见的意思是 “转而做某事；突然改变行为去做某事”，常带有一种行为或态度上的转变意味。 例句： He said he would help me, but then he turned around and refused.（他说会帮我，可接着却转而拒绝了。这里体现出从答应帮忙到拒绝的行为转变。） She criticized the plan at first, but later turned around and supported it.（她起初批评这个计划，后来却突然改变态度转而支持它。表明了态度上的转变。）