Three key websites to improve your pronunciation:

When you want to check the pronunciation of a word, you know that you can use Wordreference or howjsay.com.

However, if you want to practice with this word in context and in a sentence (and this is better to improve your accent), here are two websites you could/should use!

The first one is ReadSpeaker and enables you to listen to any text of your choice. You can also select what kind of accent you would like (American or British, male or female...).

The second one is Acapela Group and works the same way but it doesn't really work with long sentences/passages.

iSPEECH:

Here is the iSpeech website on which you can listen to a text read by a woman or a man with an American or a British accent. You can also download the recording if need be!