43.A.when B. until C.while D.if
42.A.cause B.make C.use D.allow
41.A.white B.blue C.green D.yellow
40.A.passing B.getting C.giving D.dying
39.A.alive B.healthy C.dead D.ill
38.A.way B.method C.habit D.tradition
37.A.feel B.believe C.wish D.think
Mom had a way with all things 41 . My sister and I always joked, “Mom could 42 a telephone pole grow leaves and bear fruit.”
Why can’t I? I thought. Still, I couldn’t bear to throw the dead plant away. Instead, I placed it into a dark corner of our bathroom. I didn’t even water it. I just left it there 43 I could deal with it.
My husband asked me if I was going to wear a white flower to church that Mother’s Day. “Yes,” I told him, “but I need a 44 gardenia.” I added silently.
Sunday morning I woke up early to get dressed and made for the 45 . Still 46 , I walked to the bathroom. Suddenly I was woken up by a pleasant scent (香味). I pushed the door open and stepped into the bathroom. That morning I knew I would be ready to wear a small white flower for Mom. In that dark corner, 47 as if it had a light of its own, bloomed a perfect white gardenia!
36.A.everything B.nothing C.anything D.something
35.(14分)甲、乙、丙三位同学均对酵母菌的生长情况进行了探究。甲、乙两同学先配制了含有酵母菌生长所必需的各种营养成分的培养液,调节到酵母菌生长的最适pH,各取
1mL于试管中,接种等量的酵母菌菌种,放在适宜的条件下培养一段时间,进行计数。
(1)甲同学直接取培养液,用血球计数板制成装片,在显微镜下进行计数,观察到的图像如右图所示。已知计数板方格总边长为1mm,涂抹厚度为0.1 mm。
①在从试管中吸出酵母菌培养液时,为了确保随机取样,必须 。
②若计得每一小格中酵母菌平均为10个,则该1mL培养液中共含有酵母菌约 个。
(2)乙同学将500个红细胞与该1mL培养液混匀后制片观察,进行随机统计,结果如下:
|
视野1 |
视野2 |
视野3 |
视野4 |
红细胞数(个) |
21 |
17 |
22 |
20 |
酵母菌数(个) |
102 |
98 |
106 |
94 |
则:①该同学调查模拟了种群密度调查中的 (方法)原理。
②该1mL培养液中共含有酵母菌大约 个。
(3)丙同学欲探究pH对酵母菌生长的影响,他的实验如下,请补充完整。
①配制含酵母菌生长所必需的各种营养成分的培养液,各取2mL加入数支试管中;
② ;
③ ;
④ 。
34.( 9分)在做土壤中分解尿素的细菌的分离与计数的实验时,甲同学筛选出的菌落与其他同学不同,并且他在设计实验时并没有设置对照。思考下列问题:
(1) 你认为出现甲同学这种结果的原因可能是 和
(2分)。
(2) 要帮助甲同学排除可能影响实验结果的因素,需要设置对照实验,实验方案有两种:一种方案是可以由其他同学用与甲同学 进行实验,如果结果与甲同学一致,则证明甲同学 ,如果结果不同,则证明甲同学存在操作失误或 的配制有问题。另一种方案是将甲同学配制的培养基在不加 的情况下进行培养,作为空白对照,以证明培养基是否受到 。
(3)在105稀释度下得出3个平板上菌落数的平均值是63,则每克样品中的菌落数为 。
(4)怎样初步鉴定某中细菌能够分解尿素?
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