现有反应:①Zn+CuCl2═ZnCl2+Cu
②Cu+2AgNO3═Cu(NO3)2+2Ag
③Cl2+2NaBr═2NaCl+Br2
④Br2+2NaI═2NaBr+I2
Mary used to ________ to work, but she is used to ________ to work now.
下列函数图象均与x轴有交点,其中能用二分法求函数零点的是____.
下列旅游资源属于贵州省的是( )