若△ABC∽△A′B′C′,相似比为1:2,则△ABC与△A′B′C′的面积的比为( )
A:1:2
B:1:4
C:2:1
D:4:1
小杨用如图所示的装置进行“探究平面镜成像特点”的实验。实验步骤如下:
①将一块薄玻璃板竖直立在铺有白纸的水平桌面上; ②取两盏完全相同的灯A和灯8,点亮玻璃板前的灯A,并移动玻璃板后的灯B,使它与灯A在玻璃扳后所成的像完全重合,并用笔在白纸上标记出灯A和灯8的位置;⑧多次改变灯A的位置,重复前面的步骤;④用刻度尺分别测量灯A和灯8到玻璃板的距离。在此实验中:
-6+0-10=____
根据句意和首字母提示完成下列句子。There are sixty m____ in an hour.He is ill, and his i____ makes us feel sad.A lot of t____ are visiting the Great Wall, so it is very crowded.Good food and e____ help me to study better.It is n____ to eat a balanced diet.