Hello,<br/><br/>Could you correct these sentences, please?<br/><br/>Mr. Smith's wife is an engineer, and his sister is a doctor.<br/><br/>Mr. Smith's wife is an engineer, but his sister is a doctor.<br/><br/>Mr. Smith wife is an engineer, while his sister is a doctor.<br/><br/>Mr. Smith wife is an engineer, (but, and, while) his sister - a doctor.<br/><br/>Thanks