—Yes,please.
A:Do
B:Are
C:Would
D:Is
①当n=1时, 12+1 <1+1,不等式成立.
②假设当n=k(k∈N*)时,不等式成立,即 k2+k <k+1,则当n=k+1时, (k+1)2+(k+1) = k2+3k+2 < (k2+3k+2)+(k+2) = (k+2)2 =(k+1)+1,∴当n=k+1时,不等式成立.
则上述证法( )