How many _____ are there in a week?[ ]
A. weeks
B. days
C. day
D. year
答案：B
功能矫治器的适应证中引起的中线不调的是（）
A.下颌乳尖牙早失
B.乳尖牙磨耗不足
C.上颌侧切牙早失
D.一侧乳磨牙早失
E.下颌髁突肥大
