—Peter, how old is your father this year?
—______. And we just had a Party for his ______ birthday last weekend.
A:Fortieth; forty
B:Forty; forty
C:Forty; fortieth
欧洲人形成以乳畜产品为主要食物的饮食习惯是因为:欧洲( )
yo____你
小明学习了力的知识后,对静止在水平桌面上的文具盒来进行分析,下列说法正确的是( )