日期:
来源:雅诚德英语网
The invention relates to a teaching aid for communication between teacher and students: hand-up device.
本发明涉及一种用于师生之间通信的教具:手动装置。
The invention relates to a teaching aid for communication between teacher and students: hand-up device.
本发明涉及一种用于师生之间通信的教具:手动装置。