for these reasons we're welcoming back everyone who has been on a study tour in previous years. it is divided into two compartments, in the one, a, is placed the ice, at the end of which are two channels, b, through which the water can run off; c is the other compartment, in which is placed plaster of paris or some non-conducting substance, and has two holes, d, through which it can be filled. personally i turn this off too, so that i don’t accidentally open the menu, but it’s switched on by default and it does make things faster. 