Question

Jack ___________ his homework after lunch.

1. A.
   isn't do
2. B.
   doesn't
3. C.
   don't do
4. D.
   doesn't do

Answer 1

D
分析 A项错，否定实义动词应用助动词do加not形式，不能用be加not。B项错，doesn't是助动词用来否定实义动词，不能单独作谓语。C项错，助动词do有人称和数的变化。本句主语为第三人称单数，应用doesn't，所以D对。