This case really bothers me while I am speaking. Here is the situation: I have a group of four students. Each has the textbook named "Gandhi Readers". So, there are four textbooks, yet there is only one kind (Gandhi Readers). Now, when I wanna tell them to close the textbooks and put them in their bags, may I say "close your TEXTBOOK and put it in your BAG, please" for the reason of 1-1 correspondence?
yes, at least that is what every other teacher does. if you say close your textbooks, well, students (those that actually pay attention at least) will almost ALWAYS think you are referring to them with those kinds of questions. BUT, in some cases it's fine, so it really depends on your students personalities