句子改错。

Hurry up, and we'll be late.

____ 

如图为大肠杆菌DNA分子的局部结构示意图．请据图回答：

（1）图中1表示____ ，2表示____ ．1、2、3结合在一起的结构叫____ 

（2）图中3有____ 种．中文名字分别是____ ．

（3）从主链上看，两条单链方向____ ，该DNA分子应有____ 个游离的磷酸基．

（4）若该DNA分子共有a个碱基．其中腺嘌呤有m个，则该DNA分子复制4次，需要游离的胞嘧啶脱氧核苷酸　____ 　个．

（5）假定大肠杆菌只含¹⁴N的DNA的相对分子质量为a；只含¹⁵N的DNA的相对分子质量为b．现将只含¹⁵N的DNA放到含¹⁴N的培养基中培养．子一代DNA的平均相对分子质量为　____ 　，子二代DNA的平均相对分子质量为　____ 　．

拼写音节，指出声调。

任务型阅读

      One day Mrs. Thomas goes shopping（购物）. She goes into a big supermarket. She buys many things. She buys two hamburgers. They are 2 dollars each. She buys some French fries, l dollar. She buys some fruit, too. Bananas are 2 dollars and strawberries are 4 dollars. She also buys a T—shirt, socks, shorts, a dress, a hat and a bag. The T-shirt is 4 dollars. The socks are 1 dollar, and the shorts are 10 dollars. The dress is 7 dollars. The hat is 3 dollars and the bag is 6 dollars.

根据短文内容完成表格