下列属于主物和从物关系的是( )。
A．月亮与星星 B．张某的拖拉机与李某的拖犁C．墙和土地 D．张某的钥匙和锁
参考答案：D
动物细胞中不含有细胞壁．（______）
—Let's go to Xihui Park tomorrow morning!
—Sorry, I can't go with you. My mother is ill and I must _____ her. [ ]
A. look at
B. look like
C. look after
D. look for
t