Last term,Peter was ____ at home.His parents were doing busines in another city. He felt lonely,so he often turned on the computer and played computer ____. However, sitting in front of the computer for a long time is ____ for him. And he spent little time on his study.He failed his exams.Luckily,his parents ____ his problem in time.They decided to come back home.Peter studies hard now.So far,he has made progress in his study.He ____ he can catch up with his classmates soon.

细胞核与细胞质之间大分子物质交换的通道是（  ）

长期受电磁辐射可引起人头昏、头痛、失眠等症，科学家发现富含维生素的食物具有较好的防辐射损伤功能。下列食物中富含维生素的是（   ）