The equator is an imaginary line around the middle of the earth.

赤道是一条假想的环绕地球腰部的线。

《牛津词典》

The equator is an imaginary line around the Earth.

赤道是围绕着地球的一条假想的线。

youdao

The Earth spins on an imaginary line called an axis that runs from the north pole to the south pole, while also orbiting the sun.

地球绕一个贯穿南极点和北极点的假想轴旋转，这个假想轴称为地轴。 同时也绕太阳公转。

youdao

One line is the equator. It is an imaginary line around the widest part of the Earth.

VOA: special.2010.07.14

At bedtime, Mary Ann would draw an imaginary line down the middle of the bed, and admonish me not to cross it.

CNN: CIA wife tells life story in 'My Spy'

Councillor Peter Wheatley said Natural England had agreed for the "imaginary" line to be moved but was waiting for a written confirmation.

BBC: Salt marsh on Cleethorpes beach to be pushed back 30m

Although, this path is only apparent since the Earth is also moving and the Time spent by the stone to reach the ground has also changed to some degree that imaginary vertical line.

FORBES: Colliding Galaxies Provide A Glimpse Into Our Future