如图,两圆相交于A,B两点,小圆经过大圆的圆心O,点C、D分别在两圆上,若∠ADB=110°,则∠ACB的度数为( )
A:35°
B:40°
C:50°
D:80°
等质量的氮气和氧气中,所含分子数较少的是____
6 C
12.01
7 N
氮
14.01
8 O
氧
16.00
____ is not good to play computer games so much. (That/It)
教学用直角三角板,边AC=30cm,∠C=90°,tan∠BAC=33 ,则边BC的长为( ).