用秦九韶算法计算多项式f(x)=3x6+4x5+5x4+7x2+8x+1,当x=4时,需要做乘法和加法的次数分别是( )
A:6,6
B:5,6
C:5,5
D:6,5
下列句子没有语病的一项是( )
________number of students went to visit that school last Sunday.
5-____=3