题目

Many years ago, when we were a young couple with two small children, aged 2 and 4, we were practically impecunious. My in-laws lived from hand to mouth, so we didn't expect any help from them. My parents lived a great distance away, and I was too ashamed to let them know about our situation.My husband was trying to earn a living with an old pick-up truck, carrying groceries for local shopkeepers, but it was constantly breaking down. It took almost all the money we had to have it fixed. The truck was also the only means of transportation for us.We lived in the countryside, and we always used th小梅用显微镜观察玻片时，在视野中看到一污点，移动玻片和转动转换器（装有物镜）污点始终不动，则污点最可能在（ ）A.反光镜上B.目镜上C.玻片上D.物镜上