【单选题】A person ______ is more likely to become a genius.
A.
whose parents are clever
B.
often thinking about difficult problems
C.
often helped by his parents and teachers
D.
born with a good brain and putting it into active use
【单选题】标有额定值为“220V、100W”和“220V、25W”白炽灯两盏将其串联后接入220V工频交流电源上,其亮度情况为( )
【简答题】对于人眼来说,若每秒播放大于____帧就会产生平滑和连续的画面效果。
【判断题】三个学生的成绩不同,因此存在三个变量。( )
【单选题】衡量一个区域经济社会稳定程度的重要指标的是()
【单选题】This camera is too expensive. I ’ d like a _____ one.