题干

在甲、乙两支试管中分别加入等质量的金属锌片和镁片,再加入等质量、等质量分数的稀盐酸,充分反应后,甲试管中盐酸过剩,乙试管中镁片过剩,将两试管中剩余物都倒入废液缸中,充分混合后固体消失,废液缸溶液中没有任何不溶物.

提出问题:废液缸中含有什么溶质呢?

猜想与假设:童童同学猜想:MgCl2

婷婷同学猜想:MgCl2   HCl

小宇同学猜想:ZnCl2    HCl

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      The freezing Northeast hasn't been a terribly fun place to spend time this winter, so when the chance came for a weekend to Sarasota. Florida. my bags were packed before you could say “sunshine. I left for the land of warmth and vitamin C(维生素C), thinking of beaches and orange trees. When we touched down to blue skies and warm air, I sent up a small prayer of gratefulness.Swimming pools, wine tasting, and pink sunsets(at normal evening hours, not 4 in the afternoon) filled the weekend, but the best part—particularly to my taste, dulled by months of cold­weather root vegetables—was a 7 a.m. adventure to the Sarasota farmers'market that proved to be more than worth the early wake­up call.

      The market, which was founded in 1979, sets up its tents every Saturday from 7 a.m. to 1 p.m., rain or shine, along North Lemon and State streets.Baskets of perfect red strawberries; the red­painted sides of the Java Dawg coffee truck; and most of all, the tomatoes:

amazing,large,soft and round red tomatoes.

      Disappointed by many a broken, vine­ripened(蔓上成熟的) promise, I've refused to buy winter tomatoes for years. No matter how attractive they look in the store, once I get them home they're unfailingly dry, hard, and tasteless.But I homed in, with uncertainty, on one particular table at the Brown's Grove Farm's stand,full of fresh and soft tomatoes the size of my fist.These were the real deal—and at that moment, I realized that the best part of Sarasota in winter was going to be eating things that back home in New York I wouldn't be experiencing again for months.

       Delighted as I was by the tomatoes in sight, my happiness deepened when I learned that Brown's Grove Farm is one of the suppliers for Jack Dusty, a newly opened restaurant at the Sarasota Ritz Carlton, where—luckily for me—I was planning to have dinner that very night.Without even seeing the menu, I knew I'd be ordering every tomato on it.