⑴ ____
⑵ ____
⑶ ____
⑷ ____
A. The hat is beautiful. It's size 5.
B. These shoes are new and nice.
C. The T-shirt is too small.
D. I wear a red dress. It is size 13.
三条在同一平面(纸面)内的长直绝缘导线组成一等边三角形,在导线中通过的电流均为I,方向如图所示.a、b和c三点分别位于三角形的三个顶角的平分线上,且到相应顶点的距离相等.将a、b和c处的磁感应强度大小分别记为B1、B2和B3,下列说法正确的是( )
函数y=log12x2-2x的单调递减区间是____