he is only seven years old, he knows a lot about science.( )
But
Though
So
Rick has learned a lot about Chinese culture _____ he came to China.
--Sorry, I overslept. I forgot to set the alarm.--Your clock ________. Perhaps you should buy a new one.
Be quick, we’ll be late for the meeting.
I still remember my first teacher __________ we haven’t seen each other for many years.
They have been friends __________ they were at primary school.