Now Helen's family __(be) at home and __(watch) TV.为什么用watching?

Now Helen's family __(be) at home and __(watch) TV.为什么用watching?
Now Helen's family __(be) at home and __(watch) TV.
为什么用watching?

Now Helen's family __(be) at home and __(watch) TV.为什么用watching?
are watching

is watching
family 这类词叫做 集体名词。当我们把它当作一个整体的时候，就是单数；......