进口开拆环节如因秘密载体破损发现其内件纯属非秘密载体，应通知（）局处理。
参考答案：收寄
---John is said to have learned Italian in Italy for five years.
---_______ he speaks it like a native speaker.
A．No doubt
B．No problem
C．No wonder
D．No curiosity
以下哪个是自然界存在的易于发生裂变的核素：（）。
A、铀-235
B、铀-233
C、钚-239
