He ______________ to Beijing the day before yesterday. [ ]
A. go
B. went
C. going
D. goes
答案:B
植物病害的流行必须同时具备以下3个因素:一是(),二是(),三是()。
洁治术后不需做()
A.用尖探针检查牙石是否去净
B.用3%H2O2冲洗牙周袋
C.龈沟内上药
D.立即做根面脱敏
E.检查牙龈是否损伤