黑色活动铅笔芯
black propelling pencil refill
红色活动铅笔芯
red propelling pencil refill
蓝色活动铅笔芯
blue propelling pencil refill
镀铂铅笔芯电极
Pt-modified pencil electrode
游憩体验活动
experience of recreation activity
游憩活动
recreation action
recreational activity
Tourist and Recreational activity
游离端活动义齿
distal extension removable partial denture
由…发起的植树活动
the tree-planting drive sponsored by