分隔口腔前庭和固有口腔的结构是()、牙跟和牙槽骨弓。
参考答案:上下牙弓
We can read the time 3:45 as ________.
A.three and forty-five
B.fifteen past three
C.a quarter to four
D.a quarter past three
滚动轴承代号0304中04代表()。
A.轴承内径
B.轴承外径
C.轴承类型
D.轴承承受负载