To complete the article using the Simple Past Tense, we need to transform each verb into its past form. Here’s how the article should look once complete:
We are pleased to announce the appointment of Mrs. Teicher as head of quality control. Maria studied chemical engineering at the University of Utrecht and then completed an MBA at Claremont College. After graduating she decided to work with ChemTech Supplies in Belgium. She became assistant production manager in 1989 and she helped to develop ChemTech's Multivit pharmaceutical range. Maria left the company in 1991 and joined Volcker Foods of California as head of research and development. She spent two years in the United States. Last year she briefly visited our Milan plant and was so impressed that she decided to return to Europe.