昆虫幼虫不同组织的细胞中，同一条多线染色体上横带的排列模式是一样的。这表明在发育过程中，胚胎细胞的基因组依然保持（）。
参考答案：恒定
用括号内所给动词的适当形式填空。
1. It _ (be) very windy yesterday. So we had to stay at home.
2. —Did you _ ( go) to the park last week?
—Yes, I _ ( do).
3. His funny joke _ ( make) me laugh yesterday.
4. I am __ (real) sorry. I'm late.
5. He often _ ( play) basketball with his classmates.
系统
