Only when I left home to go to college ___ how much my mother had done for me.
The policeman warned the driver _______ so carelessly.
When we visited Hainan again ten years later, we found it changed so much that we could hardly _______ it.
—Your food is very delicious! —_______.
Tim, ______ you ______ your homework yet?
Judging by her _______, Jane must be a southerner.