胶质的密度是()。
A.稍大于1
B.等于1
C.小于1
D.稍小于1
参考答案:A
Below ____ an article about advertisements ____ by a student for her English project.
A.are; writing
B.be; to be written
C.being; written
D.is; written
已知关于x的一元二次方程x2+bx+7=0的一个根为x=1,那么b+8=______.