I'm sorry I didn't phone you, but I've been very busy __________ the past couple of weeks.
The boy is the equal of the girl, _____ intelligence is concerned, but he doesn’t work hard at all.
They are singing and dancing to _______ their high spirits despite great hardships.
I recommended ________ an English-Chinese dictionary, which I thought would be of great help to his studies.
It is the day October 1st, 1949 _____ the People’s Republic of China was founded _____ we’ll never forget.
No one knows exactly when the first people arrived in _______ is now called California.