Into the dark apartment ___ , who was quite surprised when everyone shouted “Happy birthday!”
________ for children, the album became popular with parents ________ it came out.
I admire my English teacher. I can remember very few occasions ________ she stopped working because of ill health.
—Did you know more about the mine accident?—Oh,sorry,I had no idea. I ________ the Rescue Center now.
—________ you interrupt now? Can't you see I'm on the phone?—Sorry Sir, but it's urgent.
As is reported, it will be more than 20 years ________ humans are able to walk on Mars.