Some people are too bull-headed to actually do their own homework.
Idiom
No, the idiom is only used to refer to rain.
A "china closet" means a closet or piece of furniture where you store fine china, which means dishes made out of china (not the country China). The idiom "a bull in a china closet" is used to express what it would be like if you had a bull in a china closet: all the china dishes would be broken. So if someone is "like a bull in a china closet", they are running around causing trouble or breaking things. "I Was Born In A China Closet" lol
An idiom usually is a sentence, or part of one. It certainly can be used as part of a sentence. The way to tell if it's an idiom is if it makes sense the way it's literally written.
Bull Terriers were first used for dog fighting and bull baiting, and today their main function is companionship.
This is not used as much as it once was, but people will know what you mean if you use it; it's not obsolete.
This is unclear -- do you mean "what are some idioms used in the movie?" Because "inception" is not an idiom. It's an ordinary word.
bull sperm is used to make babys
Some common conjunctions used to join simple sentences and form compound sentences are "and," "but," "or," "so," and "yet."
The bull. In Spain they have 'fights' between a man and a bull.
"Shooting the breeze" or "shooting" or "throwing the bull" (bull being short for bull dung) means to kill time by engaging in idle chitchat. This term is usually applied between men. The idioms (and their tendency to be used with men) showed up in the early 20th century and come from the imagery of the Old West. Cowboys and other folk with nothing to do would find ways to kill time by, say, shooting into the air at nothing in particular (shooting the breeze) or playing around with bull droppings (throwing the bull).
The word "should" be used in the conditional sentences.