Acollegeteacheroncegavealivelyclasstohisstudents. Heb...
问题详情:Acollegeteacheroncegavealivelyclasstohisstudents. Hebeganbyholdingupaglass(1)somewaterinit.Hehelditupforalltosee,andaskedthestudents,"(2)doyouthinkthisglassweighs?" "50g!""100g!""125g!...