classes:  lecturer. When you're lecturing, your mouse doesn't show up on the projection screen, so it's hard to hear, so you don't know where you're talking on the screen, which makes it hard to understand.  curriculum. When you're lecturing, your mouse doesn't show up on the projection screen, so it's hard to hear, so you don't know where you're talking on the screen, which makes it hard to understand.  facility. When you're lecturing, your mouse doesn't show up on the projection screen, so it's hard to hear, so you don't know where you're talking on the screen, which makes it hard to understand.  general. When you're lecturing, your mouse doesn't show up on the projection screen, so it's hard to hear, so you don't know where you're talking on the screen, which makes it hard to understand.