—We are planning to have a casual get-together this Saturday or Sunday. Are you coming?

— ________. I’ve got rather a full day this weekend.

A．I hope so

B．Sounds great

C．I’m afraid not

D．You’d better not

拔腭侧断根时，牙根阻力突然消失，拔牙窝空虚，捏鼻鼓气时拔牙窝无气体溢出，可能为（）。

A．牙根进入上颌窦

B．牙根进入鼻腔粘膜上

C．牙根进入腭部粘膜下

D．牙根进入上颌窦粘膜下

E．牙根进入颊侧粘膜下