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A quadratic expression is of the form ax ​2 +bx+c. It is often useful to know what values of x will make the expression equal to 0; these are known as the roots of the equation. An easy way of seeing what th...

The best long-term advice I can give is that you have got to practice speaking the language as much as possible. Try to organise weekly sessions with teachers/language assistants/online tutors to get used to...

The chloroplast has a cell membrane like most cells/organelles. They are long and oval shaped with a similar shape/size to bacteria. Inside the organelle, the grana stack up like disks on top of one another....

An atom is made up of electrons, protons and neutrons. Electrons have a negative charge (-1), protons have a postive charge (+1) and neutrons have a neutral charge. Atoms must have a neutral charge so theref...

White blood cells in the body can attack pathogens, which are micro-organisms which cause disease. The white blood cells can ingest the pathogen, produce antibodies which destroy a particular pathogen, or pr...