1·Someone pulls the thumbtack out of the tire, which makes it hard for the owner to find where the hole is.
有人按了图钉再拔下来，这样车主找不到窟窿在哪儿，补胎时更困难。
2·He pinned up the notice with a thumbtack.
他用图钉将通知挂起来。
3·"Ouch!" cried the principal. "There is a thumbtack in this chair!"
“哎呦！”校长叫道，“这把椅子上有个图钉！”
4·I worry that Microsoft is introducing Thumbtack at a bad time.
我担心，微软推出了图钉在一个坏的时间。