a circle of的用法和樣例：
例句
- Some boys were engaged in a ding-dong battle on the playground surrounded by a circle of gaping class-mates.
一些男孩在操場(chǎng)上打斗得難解難分，圍觀(guān)的同學(xué)看得目瞪口呆，十分驚訝。 - A wheel with a circle of pins at right angles to its face, used as a tripping device.
針輪，銷(xiāo)輪一種輪子，其表面插著(zhù)一圈針，用來(lái)做陷阱設備
