Stringa=aaa;则执行a.concat(bbb)后a的内容为aaabbb。

单项选择题By tring to adjust its location aloft based on erroneous data, the drone actually started to head directly toward the desert floor. Please match the name of the feature with the sentence.

单项选择题Stringa=Hello;则执行a.replace(e,f)后a的内容为Hfllo。