后腭杆应位于
A.上颌侧切牙、尖牙之间
B.上颌硬区后部第一、第二磨牙之间
C.上颌硬区第一磨牙之前
D.下颌第一、第二磨牙之间
E.上颌第二磨牙以后
参考答案:B
I ____________ and danced with my new friends.[ ]
A. singed
B. sang
C. sing
There was ______ time ______ I hated to go to school.
A.a; that
B.不填; when
C.a; when
D.the; when