Explanations:Chennai, the capital city of Tamil Nadu, is known for its moderate climate and significant trade activities. The climate of Chennai is influenced by its coastal location, which results in a warm and humid environment throughout the year. The average temperature in Chennai ranges from 20°C to 35°C, making it a warm city with high humidity levels. This climate is considered moderate compared to other parts of India, but it is not cold enough to require woollen clothes. Therefore, the statement that woollen clothes are needed in Chennai is incorrect.
On the other hand, Chennai is a major port city and the Chennai Port is one of the oldest and largest ports in India. It plays a crucial role in the country's trade and commerce. The port handles a significant amount of cargo, including imports and exports, and is a vital link for international trade. The port's strategic location on the Bay of Bengal makes it an important hub for maritime trade, connecting Chennai to various parts of the world.
Thus, the correct statements are that Chennai has a moderate climate and that the Chennai Port is used for trade. The statement about the need for woollen clothes is incorrect due to the warm climate of Chennai. Understanding the climate and trade aspects of Chennai is essential for comprehending the city's geographical and economic characteristics.