外径千分尺的用途有哪些？
参考答案：
外径千分尺的主要用于测量量程范围内的两平面之间的距离和圆柱形产品的外径尺寸。
完成英语句子
1. (有)two maps and some pictures on the wall.
2. Her father (没有) any sister.
3. (有) some water in the cap.
4. —What's his (爸爸的) job?
—He is a teacher.
5. I can see (十九) students in the classroom.
6. Tom's school is a beautiful school and it's (英语) school.
石油蒸馏产品的电导率往往都小于（），属于静电储集体。
A、50ps/m
B、100ps/m
C、120ps/m
