Which phrase best completes this conversation? Marie: Je veux acheter un vieux livre et des bijoux faits à la main. Raoul: Tu dois aller . A. au centre commercial B. au supermarché C. au marché aux puces D. à l’épicerie

A) Au centre commercial

Explanation:

This is because Marie is asking where to buy books and jewelry and so the shopping center would be the best option to go to buy it at as it says tu dois Aller which means you have to go. B means a supermarket, C means the flea market and D is a food shop.

Lysozyme - Chemical barrier;
Lysozyme is a substance found in saliva, tears, and mucus that destroys the cell wall of bacteria
Skin- physical barrier
The skin has closely packed cells and it is  tough, flexible and also water proof. 
Phagocytes -Biological barriers;
They are types of white blood cells that help protect against pathogens. 
Langerhans cells- Biological barriers;
These are specialized cells in the skin that identify pathogens that enter the body and carry them to the lymph nodes for destruction. 
Acid and Oil (skin secretions) - Chemical barriers;
These are secretions from the skin that help to keep microorganism from entering the body
Sneezing and coughing - Physical barriers.
Type of reflexes that helps keep microbes and pathogens from gaining access to the body systems.