孵化
参考答案：
昆虫胚胎发育到一定时期，幼虫或若虫冲破卵壳而孵出的现象。
If you have some difficulties ____ your grammar, you had better ask your teacher ____.
A．in; on some advice
B．for; for some advices
C．on; some advice
D．with; for some advice
国有林业局所属的森检机构负责执行本 单位的森检任务，但是，须经哪级林业主管部门确认？
