“记得当时年纪小，你爱谈天我爱笑。”青春的校园洋溢着浓浓同学之情，但中学阶段男女同学交往需要做到（    ）

①自重自爱  ②落落大方   ③掌握分寸 ④互不接触

读《元日》，按课文内容填空。

每年的除夕夜，听着窗外此起彼伏的鞭炮声，张大爷总会情不自禁地吟诵起王安石《元日》中的诗句“____，____。”

    Helen got up at seven thirty. Her parents and her little twin brothers went travelling in Australia and she had to take care of herself at home. She opened the fridge, but she found only three pieces of bread in it. She decided to have breakfast in the restaurant at the other side of the street. She sat at a table and the waitress came up to her and said, “Can I take your order, Helen?”

    “But you didn't show your menu to me, Miss White,” said the girl.

    “Oh, sorry! I forget it. Here it is.”

    Helen looked at the menu carefully. It was:

bread  $1.5          egg  $ 0.4

pizza  $2.5          cola  $ 0.3

sandwich $1.5        milk  $ 0.6

hamburger $2.5       coffee  $ 0.9

    Helen took out her purse and found there was only 7 dollars in it.

    “Well,” said White.“What about a hamburger, a pizza, two eggs and a glass of cola?”

    “Oh, no,” said the girl. “I'll buy a storybook this afternoon. It's 2 dollars.”

    “I see,” said the waitress. And then she brought the girl a nice breakfast.

如图所示的3种细胞结构，最有可能是细菌性痢疾病原体细胞结构的是____，你认为这种细胞是细菌的主要依据是____。