用分词结构将下面的复合句改成简单句
People always shake hands with each other when they are introduced for the first time.
                                                                        
If it is taken according to the directions, the medicine will surely work.
                                                                        
He found that the door of study was closed to him.
                                                                        
What do you think of the suggestion that was put forward at the meeting?
                                                                        
A group of people who called themselves Environ-ment Protector appealed to people to drive less.
                                                                        
While we were seated in the sunlight, we felt much relaxed.
                                                                        
As time went on, everybody became anxious about the safety of the sailors.
                                                                        
Don't get into the office unless you are permitted to.