Ok ....... a circuit relay is basically a switch... I have restored some older cars - pre circuit relays so I understand but would find it difficult to thoroughly explain . Its worth while just Googling Circuit relay.. lots of information on a more technical level.

Hi Mehrdad, A couple of examples might help, "Must" and "Have to" are used in the UK but without context its a little difficult to answer

As Duncan noted, News in slow Spanish is quite good and you do get the first story free , its for intermediate/ advanced. I also listen to podcasts form Espanol con Juan /1001 reasons to Learn Spanish. Spanish with Vincente. Many of these Youtube language tutors have some form of Podcast. How to Spanish ( Mexican ) are also great, many are 30 mins plus but the speed is measured and language clear and varied. I also listen to Radio Ambulante which is more of a current affairs/ new programme ( it does have a heavy political slant )and at time some of the audio can be quite challenging along with its Latin American vocabulary, I'm more Spanish from Spain and mentioning "Spanish from Spain" (youtube) Reyes is as mad as a hatter but a great teacher. Espanol Automatico also great..( also Youtube) I'd say all of these are for B1 ( some might be a little challenging ) B2 I've just done a quick search on my iPhone and several podcasts popped up so just do a search

Hi Shami, what you are probably hearing is "D" Wader, if you do a Youtube search for differences between UK English and US English you will encounter many videos explaining how the pronunciation varies between the two Countries... As a British person I would pronounce the "T" in Water. Supper holly and English with Lucy would be a good starting point.