根据短文内容和所给中文提示，在空白处写出单词的正确形式，每空限填一词。

On the night of the play, Jack was at the theatre early and he was 小题1:  (已经)dressed in a suit of policeman’s clothes long before the end of the first scene.  小题2:   (当然) he looked the part all right, he thought as he admired himself in the mirror. Then he suddenly felt nervous. Of course he knew it’s 小题3:   (必须的)for him to stay cool. But it was his first time to have a part in a play. How could he face all those people watching the play? He put his head in both of his 小题4:   (手)and tried to remember the 小题5:   (建议)from the experienced actors, but 小题6:   (没有什么)came to his mind. A knock on the door made him look up. He was to go on stage in the second scene. ―Have I  小题7:  (错过)my part and destroyed the play for everybody ? He thought to himself. But it was only the manager. She  小题8:  (注意)how nervous he was and suggested he should stand 小题9:   (在……附近)the stage where he could watch and follow the play. It was a good way to make him 小题10:  (放松), she said. She was right, it seemed to work. In fact, the more he watched the play, the more he felt himself part of it.

铬酸钡分光光度法适用于中、低浓度硫酸雾的测定，方法所用仪器简单，易于推广使用。该方法测定的是（）离子，不能分别测定硫酸雾和（）颗粒物中的硫酸盐。