已知int[][] a= {{1,2},{3,4,5,6},{7,8,9}},a.length()=_________,a[0].length()=__________, a[1].length()=__________,a[2].length()=__________,a[3].length()=__________。
What's the features of ad slogans?
A. use of adjectives
B. use of interrogative sentences
C. use of imperative sentences
D. use of pun
E. use of simple sentences