The economy is overheated. This long-lost term in the dictionary of American economic history has once again entered people’s field of vision. 　　After the 2008…

Virus: the lowest life form without cell structure 　　Viruses are the lowest-level organisms with extremely small size and no cell structure. The size of the…

　　From ancient times to the present, no matter what cultural background, mothers will sing to their children. Music can soothe babies because auditory stimuli are…