假如检测得知一个DNA分子某种碱基的数目为x，其占碱基总数量比例为y，以下推断正确的是（  ）

完形填空

  It was very hot in the middle of summer and there were no trees 1the street. Mr. Read 2 his shop at half past five, and went 3 into the street and began walking to the bus stop. He was very 4. The sun shone straight down the street, and in a few minutes Mr. Read5very hot.

     A small boycame out of another6 in the street and 7Mr. Read. He stayed very8 him all the time, and he kicked Mr. Read's 9several times. Mr. Read looked at him 10 each time.

     After thefourth time, Mr. Read stopped, turned 11 and said to the small boy, "What are you doing? 12 following me like that! You're going to 13 my feet."

     "I'm 14, but don't stop me, please!" The small boy said, "It's very hot today, and there isn't 15shade anywhere else in the street."

小明家的电路简化后如图所示，观察该电路，下列说法中正确的是（    ）

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通常被人们称为“东三省”的是（　　）