听录音,选择正确的图片。 ( ) 1. — How do you go to the _____________? — Usually I go by subway. A. ( ) 2. — How do you go to the _____________? — I go by bus. B. ( ) 3. — How do you go to the _____________? — I go on foot. C.
【简答题】用离子-电子法配平下列反应方程式:(写明过程) (1) I - +H 2 O 2 + H + ----- I 2 + H 2 O (2) Cr 2 O 7 2- + H 2 S + H + ----- Cr 3+ + S (3) ClO 3 - + Fe 2+ + H + ----- Cl - + Fe 3+ (4) Cl 2 + OH - ----- Cl - +ClO - (5) Zn + ...