—Bill doesn't know how to improve his Chinese. Could he ask you for some _______?
—Of course.
A：suggestions
B：idea
C：answer
D：advices
在豌豆植株的叶肉细胞中，细胞质内含有的糖类和核酸主要是
中学生情绪的特点（ ）
①大都丰富而强烈 ②起伏变化也较大
③很不稳定 ④没有什么变化，比较稳定
Ben was busy taking a training class, ________ we had to wait for him for half an hour.
