A:若沿水平方向切去相同质量,p甲可能大于p乙
B:若沿水平方向切去相同体积,p甲一定小于p乙
C:若沿竖直方向切去相同质量,p甲可能大于p乙
D:若沿竖直方向切去相同体积,p甲一定小于p乙
Replacing some things in your house at the right time can make you healthier. Some researches show us when and why the following things should be replaced.
Word Box: wool羊毛 dry-clean 干洗 bacteria 细菌
如图表示人类镰刀细胞贫血症的病因,据图回答:
小丽站在平面镜前观察自己在镜中的像,她在镜中看到的像是 ____像(选填“实”、“虚”).矫正近视眼所带的眼镜,其镜片是 ____透镜.