All flights___ because of the snowstorm, we decided to take the train.

A．were canceled　

B．had been canceled

C．having canceled

D．having been canceled

混凝土拌合物的和易性包括( )等几个方面。

A．流动性、黏聚性和保水性

B．流动性和保水性

C．流动性和黏聚性

D．黏聚性和保水性