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(2) $\int_{-1}^0 d x \int_{-x}^{\sqrt{2-x^2}} f(x, y) d y+\int_0^1 d x \int_x^{\sqrt{2-x^2}} f(x, y) d y=(\quad)$
A. $\int_0^1 d y \int_{-y}^y f(x, y) d x+\int_1^2 d y \int_{-\sqrt{2-y^2}}^{\sqrt{2-y^2}} f(x, y) d x$     B. $\int_0^1 d y \int_{-y}^y f(x, y) d x+\int_1^{\sqrt{2}} d y \int_{-\sqrt{2-y^2}}^{\sqrt{2-y^2}} f(x, y) d x$     C. $\int_{-\frac{\pi}{4}}^{\frac{\pi}{4}} d \theta \int_0^2 f(r \cos \theta, r \sin \theta) r d r$     D. $\int_{-\frac{\pi}{4}}^{\frac{\pi}{4}} d \theta \int_0^{\sqrt{2}} f(r \cos \theta, r \sin \theta) d r$         
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