Any substance, such as a drug, chemical, or virus that can bring about a birth defect?

How do nicotine and tobacco cause cancer? by decreasing blood-sugar levels by damaging or changing a cell's dna by increasing heart rate by increasing phlegm and mucous production

Why is it that people at first would be nice then they shut you down? (school matter)

There is only one copy machine at your office. you have to make 1000 copies of an expense report. after you begin copying, two other employees show up in the copy room. each has to make only 10 copies each. what is the proper etiquette in this situation?