把点(2,8)代入y=ax2,
得4a=8,
∴a=2.
故选C.
A kangaroo a pouch. [ ]
A. have
B. has
C. with
铺设软帘盖堵漏洞进口时,要()。
A.把软帘的上边栓于堤顶木桩上
B.将软帘塞入洞内
C.在软帘下端坠重物
D.用土袋或散黏土盖压闭气
E.压砂石反滤