根据句意和首字母提示填空。

1. The Spring Festival is often in F______.

2. My mother's birthday is on June the t______.

3. Would you like to come to my mother's b ______ party tomorrow morning?

4. The twelfth month of the year is D______.

5. —W______ is the World Expo in Shanghai? —In 2010.

某公司发出要约后，在要约未到达受要约方之前又发传真给受要约人，声明原要约作废，根据《合同法》规定，此传真声明要约作废的行为属于( )。

A．要约撤回

B．要约撤销

C．要约生效

D．要约失效