i wonder引导什么从句

　　I wonder if you could point me in the right direction for the bus station.

　　请问您能指点我到公共汽车站往哪个方向走吗？

　　I wonder if you can help me.

　　不知您是否能帮我的忙？

　　I wonder if I should wear a coat or not.

　　我不知道该不该穿外套。

　　I wonder he didn't hurt himself jumping over that wall.

　　我纳闷他怎么从那墙上跳过去竟没摔伤自己。

　　I wonder who that letter was from.

　　我不知道是谁来的信。