—It is reported his fortune is up to $37 billion. However, he led a dog's life during his childhood.
A:had a happy life
B:lived a hard life
C:lived with a dog
若用同一显微镜观察同一标本4次,每次仅调整目镜、物镜和细准焦螺旋和遮光器,结果得到下面亮度相同的各图.试问其中通光孔通光量最大的是( )
—By bike.