染色体的数量在细胞分裂时已经（ ）
A：减半
B：加倍
C：不变
D：都不是
例：If I were in your position，I would pay close attention.
→Were I in your position，I would pay close attention.
解决问题。
Ice cream _____ my favourite food.（ )
Onions _____ my favourite vegetable.
11－____＝____ 11－____＝____
