Do you know that the first textbooks written for teaching English as a foreign language ____ in the 16th century?
_____ heat is different from temperature?
_____ 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.