如何评价一株啤酒酵母菌种的质量优劣？
参考答案：（1）外观。优良啤酒酵母呈均匀的卵圆或椭园形，大小一致，细胞膜薄而平滑等
（2）发酵度。应选择发酵度高的酵母作为生产用酵母。
（3）凝聚性。一般选择凝聚性强的酵母菌株。
（4）热死温度。一般野生酵母的耐热性比较强，其热死温度也高。
（5）发酵试验。用酵母进行小型啤酒发酵试验，若口味正常，且带芳香，说明酵母质量合格。
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| I first met her on the beach near where I live. I drive to this beach a 1 of three or four miles, whenever I'm feeling down. At that time she was 2 something. Looking 3 , she said, "Hello." I nodded,not wanting to 4 with a small child. "I'm Wendy and I'm building something," she said. "I see. But what is it?" I asked, not 5 . "I don't know. I just like the 6 of sand." A sandpiper (矶鹞鸟) flew by. "That's a 7 . Mum says sandpipers come to bring us joy." "Good-bye, joy," I thought to myself, "hello, 8 ." and walked away. My life then seemed completely out of 9 . "Come again," she called, "and have another 10 day." But the days and weeks that followed 11 to other people:naughty boys and a 12 mother. One morning I suddenly realized I needed my 13 and headed for the beach. The breeze was cool, but I walked along,trying to recapture (捕捉) the inner peace I needed. I had almost 14 the child so I was surprised when she appeared. " 16 do you live?" I asked. She pointed toward a summer cottage. Then one day, I rushed to my beach in great pain, even in no__16__to greet the girl. "If you don't mind," I said coldly, "I'd rather be 17 today." She seemed unusually 18 and out of breath. "Why?" she asked. "My mother died!" "Did it hurt when she died?" "Of course it hurt!" I shouted, misunderstanding her. When I next went to the beach, she wasn't there. Feeling 19 , and admitting I 20 her, I went up to the cottage. A woman answered the door. "Wendy, my daughter, died last week. She had leukemia (白血病). Maybe she didn't tell you." | ||||
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