The value of $1+1-2+3+5-8+13+21-34$ is
(A) -32
(B) 1
(C) 88
(D) 0
(E) -34
By grouping terms using brackets as shown, $(1+1-2)+(3+5-8)+(13+21-34)$, we can see that the result inside each set of brackets is 0 .

Thus the value of $1+1-2+3+5-8+13+21-34$ is 0 .

ANSWER: (D)