——Can I eat the cake,Mum?——Yes,you can._________you must wash your hands first.
He fell off the bike ________.
My sister isn’t in. ________ she comes back, I’ll let her call you back.
She got up early this morning _________ she could catch the first bus.
The twin sisters have learned a lot ________ they came to China.
If it tomorrow, we to climb mountains.