铅笔芯

例句：

1. 1. The pencil is madeof a thin layer of lead core.
   这支铅笔由一层薄的铅芯制成。
2. 2.The teacher asked the students to remove theirpencils from the desk before class began.
   老师要求学生们在上课前将铅笔从桌上取下来。
3. 3. The student carefully tookout his pencil core and sharpened itwith a sharpener.
   学生小心翼翼地取出他的铅笔芯，并用削笔器将其磨尖。