Questions

Add together values in corresponding positions of the top two crosses, and put the result in the lower left cross.

Calculate the difference between values in corresponding positions of the top two crosses, and put the result in the lower right cross.

Finally add together the values in corresponding positions of the lower two crosses to give the values in the central cross

Online marketing is the exchange of products and services between the buyers and sellers on the internet.It is also known as e-marketing or internet marketing or online advertising. It may take the form of : 

a.B2C where the products are sold directly to the customers. 

b.B2B where trading networks or auction sites maybe used to reach out to the new customers and serve the existing one

c.C2C where one customer may further sell the product to another customer.

Examples of online marketing may include banner ads, blogs, social network advertisement.

Saw dust contains carbon which is oxidised to carbon  dioxide by concentrated nitric acid;