Bring the flowers into a warm room _____ they’ll soon open.
The old man had three sons, all of ____ died during World War Ⅱ.
I have bought two pens, ____ write well.
Do you know the reason ____ she has changed her mind?
He failed in the exam, ____ proves that he wasn’t working hard enough.
During the week ____ he tried to collect materials for his article.