A:sunglasses
B:a T-shirt
C:an umbrella
⑴How can you get to the school ?____
⑵Happy birthday !____
⑶What's the weather like in summer ?____
⑷May I speak to Mike ?____
⑸Where is your aunt from ?____
A、It's cold .
B、Shenzhen .
C、Thank you .
D、Take bus No.4 .
E、Yes , speaking .
假如一粒核桃种子燃烧,能使锥形瓶内的30ml水由25℃升高到30℃(提示:1 毫升水每升高1℃,需要吸收4.2 焦的热量),锥形瓶内的水吸收了____ 焦的热量.实际上此粒核桃种子全部燃烧产生的热量比上述热量____ (填多或少)
下列育种措施,可以增加植物突变体出现的是