—When did your cousin begin to show his interest in medicine?—It was a Saturday __________ she noticed her uncle experimenting on a frog in his lab.
_____ his face, the young man must be over 20.
He said_____his sister had passed the entrance examination of college, and_____she would go to college in about 20 days.
—— Would you like some wine? —— Yes, just _____.
_____ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.
He broke his legs while _____.