A：该反应是吸热反应
B：该反应是放热反应
C：铁粉和硫粉在常温下可以发生反应
D：硫化亚铁的总能量高于铁粉和硫粉的总能量
(____) He is making a birthday card.
(____) He's in his room.
(____) When is Jack's birthday?
(____) Where's Jim?
(____) Who is he making it for?
(____) What is he doing?
(____) Tomorrow.
(____) He is making it for his friend，Jack.
在炎热、干旱、多风的沙漠地区进行绿化，选择最理想的植物是（ ）
选项
筛选前
第一次筛选获得
第二次筛选获得
A
a、aa、ab、bb、b
a、aa、ab
ab
B
ab、bb、b
C
能无限增殖的ab
D
能产生特定抗体的ab
