A:43
B:45
C:54
D:34
—In five minutes, at 10: 25.
—Would you like _______ basketball with us?
—I'd love to. I enjoy _______ basketball very much.
0.004007有()个有效数字
如图所示,通电螺线管附近的小磁针处于静止状态,则螺线管A端是 ____ 极,电源的D端是 ____极.