A:①②
B:②③
C:③④
D:①④
一组数23,45,67,89…按一定的规律排列着,请你根据排列规律,推测这组数的第10个数应为( )
A number of new functions ________ to the computer since it was first invented in 1946.
某同学进行“观察叶片的结构”实验,所看到的菠菜横切面如图,请分析回答: