にほんごのれんしゅう３

Please correct the following sentences if they are wrong. I also included the intended meaning for clarification. Suggestions on improvement would be much appreciated. ありがとうございます

１。わたしはコンビニにやさいやにくをかいにいきたいです。
- I want to go to the convenient store to buy things such as vegetable and meat.

２。スーさんはとてもあたまがいいので、ロバートさんはスーさんと結婚したいです。
- Because Sue is very smart, Robert wants to marry her.

３。トムさんはせがたかい男ですが、トムさんのあねえさんはせがひくいおんなです。
- Tom is a tall man, but his older sister is a short woman.

４。ロバートさんはだいがくにいかなかったから、いましょくどうにつとめています。(Can someone explain to me the difference between つとめる and 働く?)
- Because Robert did not go to college, he now works for a cafeteria.

５。スーさんははなをみるのがすきなので、こうえんにしゃしんをよくとりにいきます。
- Because Sue likes to look at flower, she often goes to the park to take pictures.

６。こどものとき、ロバートさんはちょっとふとっていました。
- When Robert was a kid, he was a little chubby.

７。わたしのクラスにはかみがながい女の人がよにんいます。(I am not sure this is grammatical)
- There are four people with long hair in my class.

８。スーさんはけんちくがくにきょうみがあるので、イタリにびじゅつしをべんきょうしにきました。
- Because Sue is interested in architecture, she came to Italy to study art history.

９。わたしのにほんごのクラスにはオーストラリアじんがふたりとアメリカじんがひたりいます。(I am not sure if this is grammatical either)
- There are two Australians and one American in my Japanese class.

１０。ロバートさんはいまべんきょうしているので、へやのもんこをしめました。
- Because Robert is studying, he closed the his room's door.