What's your uncle? [ ]
A. She's a worker.
B. He's a driver.
答案:B
一块平行四边形的地底长60米,高25米,在这块地的正中修建了两条宽5米的“十”字形道路.
(1)选用______:______的比例尺作图.
(2)计算这块地可耕种的实际面积.(把图画在下面)
微分方程(y")2+(y')3+sinx=0
A.1
B.2
C.3
D.4