Teachers are generally not allowed to demand permanent medical certificates from their students. In most cases, teachers may request a medical certificate for a specific period of absence due to illness, but they cannot demand a permanent medical certificate. Permanent medical certificates are typically only required for specific medical conditions that may affect a student's ability to participate in certain activities or require accommodations. It is important for teachers to respect the privacy and dignity of their students when requesting medical documentation. **

It is generally more effective to make polite requests rather than demanding something. Begging can come across as desperate and may not be well-received, while demanding can be seen as aggressive and off-putting. By politely asking for what you need or want, you are more likely to get a positive response and maintain good relationships with others. **

Yes, mathematicians are in demand in various industries such as technology, finance, and data science. Their expertise in problem-solving, critical thinking, and analytical skills are highly valued by employers. With the increasing reliance on data-driven decision-making, mathematicians play a crucial role in developing algorithms, models, and solutions to complex problems. As a result, there is a growing demand for mathematicians in the job market. **

Yes, one can demand something if they feel it is necessary or important. However, it is important to consider the context and manner in which the demand is made. It is always best to communicate one's needs and expectations respectfully and clearly to increase the likelihood of a positive outcome. **

Yes, nutritionists are in demand as more people are becoming aware of the importance of a healthy diet and lifestyle. With the rise in chronic diseases related to poor nutrition, there is a growing need for nutritionists to help individuals make better food choices and improve their overall health. Nutritionists are also sought after in various settings such as hospitals, schools, fitness centers, and corporate wellness programs. Overall, the demand for nutritionists is expected to continue to grow as the focus on preventive healthcare increases. **

Klarna's demand can be seen as justified due to the increasing popularity of their buy now, pay later service among consumers. The convenience and flexibility it offers to shoppers, along with the potential for increased sales for merchants, supports the demand for their services. Additionally, Klarna's innovative approach to online shopping and payment solutions has helped them stand out in the market, further justifying their demand. **

ProSieben demands high-quality content that appeals to a broad audience, including popular TV shows, movies, and original programming. They also require innovative and engaging advertising solutions to reach their viewers effectively. Additionally, ProSieben seeks to continuously adapt and evolve their offerings to stay competitive in the ever-changing media landscape. **

Vodafone's demand refers to the level of desire and need for their telecommunications services and products. This includes mobile phone plans, internet services, and other communication solutions. Vodafone's demand is influenced by factors such as consumer preferences, technological advancements, and competitive pricing. The company seeks to understand and respond to this demand in order to attract and retain customers in the highly competitive telecommunications industry. **