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