It was not until late in the evening _____ her husband arrived home .
So necessary _____ it to learn about their customs that I will attend a special lecture next week.
Your son came to my class every day, but his attitude _____ he was not really interested at all.
It' s a pity that there are many teenagers _____only on-line activity is chatting with their e -pals !
- Do you mind my opening the window? -______I feel a bit cold.
Father said he would come to my graduation ceremony, he didn't, _______.