my mother is watching tv at home now.(改爲現在完成時)my mother ____

題目：

my mother is watching tv at home now.(改爲現在完成時)my mother ____ ____ tv at home for twenty
minutes
這裡只有兩個空格

解答：

My mother (has watched ) tv at home for twenty minutes.
再問： 這裡只有兩個空格
再答： 所以答案就是 has watched