Look at the woman.She __________(swim) over there.

问题描述:

Look at the woman.She __________(swim) over there.

is swimming look是现在进行时的标志

is swimming.
Look at the woman. ---看那个女人!
说这句话的时候,那个女人的动作是正在进行的,所以用现在进行时。

is swimming