7.中文：我看不清黑板。也许你需要检查你的眼睛。

　　(误)I can't see the blackboard very well.Perhaps you need to examine your eyes.

　　(正)I can't see the blackboard very well.Perhaps you need to have your eyes examined.(表示使某物被别人…，通常使用have或get+物+过去分词表示。)

　　8.中文：他命令马上开始工作。

　　(误)He ordered the work to start at once.

　　(正)He ordered the work to be started at once.(不定式作宾语补语时，若与宾语是被动关系，要用不定式的被动形式。)

　　9.中文：他试图不介入政治。

　　(误)He tried not to have mixed up in politics.

　　(正)He tried not to get mixed up in politics.(get作系动词，可代替be，后接过去分词表示被动，have无此功能。)

　　10.中文：据说他很富有。

　　(误)They say him to have been rich.

　　(正)He is said to have been rich.(say后不可接不定式，但它的被动语态后可接不定式。)

　　11.中文：那人被认为是个傻子。

　　(误)The man thought to be a fool.

　　(正)The man was thought to be a fool.(主语是动作的承受者而不是发出者，用被动语态。)