何为昆虫的龄期？
参考答案：
昆虫相邻的两次脱皮之间所经历的时间称为龄期。
Principal White has been working in the school for about 20 years, all his energy to teaching and
researching as well as the running of a healthy school. [ ]
A. devoted
B. devoting
C. to devote
D. and devote
GPRS功能取消（）生效，无套餐的客户新开通各款套餐（）生效，客户开通（）小时后生效。
