—Is it next to the library?
—_____________.
A:Yes, there is
B:No, it is
C:No, it isn't
D:Yes, she is
—Hello, Jenny. I'm doing my homework. The sums are very ____.
—Let me see. The sums are easy. Let me help you.
在一个生态系统中,已知初级消费者与次级消费者的个体数分别为N1和N2,个体平均重量分别为M1和M2,则下列四项中正确的是( )
在中国历史上规定立法、行政、司法三权分立政治体制的第一个文件是