用英文怎么表达？怎么写

　　我不知道这句话用英文怎么表达。

　　I did not know how this speech does express with English.

　　言语无法表达我的愉快心情。

　　Words cannot express how pleased I am.

　　父母可以表达对自己孩子所上学校的偏好。

　　Parents can express a preference for the school their child attends

　　她想找个简单的词来表达简单的想法。

　　She groped for a simple word to express a simple idea.

　　我想向医生们表达我最由衷的感谢。

　　I would like to express my warmest thanks to the doctors.