{"answers": "D", "options": ["f : oh , i see . some underwater plants will keep the water dirty but will let the fish swim around .", "f : so , you mean underwater plants will make the tank look much ugly but can give the fish enough air .", "f : so , you mean fish do n't love swimming around the rocks and some underwater plants are needed because they can keep the water clean .", "f : yeah , i agree with you . some underwater plants are needed because they will keep the water clean ."], "article": "f : i saw a beautiful fish in the market the other day , it was orange and blue . i 'm thinking of buying some next sunday . m : where would you keep them ? f : in that round bottle over there . m : it 's a bit small , is n't it ? f : so are the fish . m : i think you should get a tank if you want to keep fish . f : really ? m : yes , you should never keep fish in a small round bottle . they do n't get enough air . i suggest we go shopping together and look for a nice tank . f : that might be quite expensive . m : check the prices before you buy one and you ought to put a few large rocks in the tank . fish love swimming around the rocks and through holes in them . f : is there anything else that i ought to get ? m : yes , you need to get some underwater plants , for one thing they keep the water clean , also they make the tank look much prettier .", "id": "train_636"}