I can see that my father is tormenting himself with the idea that my mother----- ill if we------- at Helstore when she had first symptoms.

If it ------ to nothing else , the achievement of rationalists in education ------- it one of the truly creative movements of history with emerging sciences.

Twilight is also the result of the light scattered by particles and molecules in the atmosphere. ------ for this scattering, we------- in darkness as soon as the sun goes below the horizon.

------ the new bridges are built across bodies of water, the foundations ------ under water.

If the air------- from the ordinary electric light bulb you use in your lamp, the oxygen in the air------ the wire inside the bulb to burn out very soon.

When a particle ------ with its anti-particle , both particles ----- and energy appears in their place.

If all people ----- the same language, there ------ still-------- many differences between the language itself and the way it is used.

If the ice---- denser than water, it----- to the bottom , leaving the top layer of water exposed to water temperature.

If you------ a bowl of water in a well- heated room, the level of water in the bowl-------.

If we------ a spark to the mixture , there ------ a violent reaction, producing heat, light and sound.

If you----- to remember a large number of words without respect to their order, it -------- to group similar words together.

The dissolved nitrogen in the blood ------ a great deal of trouble if a person ----- air that is under considerable pressure .

If we----- a flake of mica between the plates , a series of beautiful spectral colours ------- on the screen.

If the water ----- rapidly, it ------ likely to wash down plant nutrients with it.

If pollination ------ and fertilization ----- , no fruit ---------.

A word ------ more likely to be remembered better, if it ----- in context with objects it represents.

If teachers ----- the student's mother tongue , translating individual words ------ a shortcut to vocabulary teaching.

If blood pressure ----- to fall , the kidneys ------- the enzyme renin into the blood where it reacts with another protein.

If there ------ little work experience , the part of the resume devoted to education ------- scholastic achievements and activities.

------ an unexpected thing should occur, don't hesitate to call us since you may not be able to solve the problem by yourself.

Our customers have the right to change the items which they buy from our shops ------ they are unused.

------ it is really necessary , may you ask for permission to go out for your personal works.

If a perceiver, under normal conditions, ------ an experience of a red object , then he------ a red object.

If only my pains ------ less, then I ------ myself better before starting the new term this year.