[填空题]
The coefficient of staa2d)wb0zorrir( nt /g8d ecg19 d zia,b6(jt, 1 b,4pjaowl2jqwh: h1-ih :bctic friction between hard rubber and normal street pavement is about 0.8. On how steep a hill (maximum anhhpq1jabij 12c, b-w4 ol hw::gle) can you leave a car parked? $^{/circ}$
