复数： thumbtacks

I press the thumbtack into the board with thumb .

我用大拇指将图钉按在木板上。

He pinned up the notice with a thumbtack .

他用图钉将通知挂了起来。

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。

Okay , is this a trick involving a thumbtack in my bottom ?

好吧，这个恶作剧不是在我屁股下放图钉吧？

In a paper to do again , " air " on the child 's name written above on a thumbtack press .

再在一架纸做的“飞机”上写下孩子的名字，上面按上一枚图钉。