用should,ought to或have to的正确形式填空
问题描述：
用should,ought to或have to的正确形式填空
He ________ (come) at 4 o'clock if the plane arrives on time.
I didn't go shopping this morning as I __________ (do) the housework
She ________ (come) to see me yesterday,but she forgot.
You _________ (ask) for permission before you left the table.
As they didn't understand,I _________(explain) everything again
答
1. should come 2. had to do 3. should have come 4 should have asked 5 had to explain