颅底陷入征病因以先天性发育畸形为常见，可与扁平颅底、寰枢椎畸形、Dandy-Walker畸形等合并存在。()
参考答案：错
某种细胞分裂时，由1个分裂成2个，2个分裂成4个……依次类推，写出1个这样的细胞分裂5次后，得到的细胞个数为 [ ]
A.32
B.31
C.24
D.25
— What do you do on the farm?
— My job is to feed (喂养) the animals, such as and . [ ]
A. horses, sheeps
B. horse, sheep
C. horse, sheeps
D. horses, sheep
