在显微镜下观察洋葱鳞片叶内表皮细胞和人的口腔上皮细胞时，都能看到的结构是（    ）

    As they walk down the halls during their years together at Shady Side, our boys and girls —— so soon to become men and women —— are learning to think, to work, to question, to be ____ and ____, to____with others, to laugh at their mistakes and to act ____ when ____ comes their way.

    Sir William Osler, a famous Canadian doctor,____ the value of ____ by saying, "No man is really happy ____ a hobby, and it makes precious little ____ what the outside ____ may be."