A：from
B：with
C：for
D：at
用显微镜观察用清水处理过的洋葱表皮细胞时，不易观察到的结构是
选择合适的句子，补全对话。（有两项是多余的）
A. What did you do yesterday?
B. Where did you go yesterday?
C. How many children were there at the party?
D. Yes, he did.
E. Why did you visit Mike?
F. No, they weren't.
G. How many children are there at the party?
A:Hello, Liu Yun. ____
B:I visited Mike.
A:____
B:Because it was his birthday yesterday.
A:Did he have a birthday party?
B:____
B:There were fifteen children at the party.
A:Were Mike's parents at home?
从1cm、3cm、5cm、7cm、9cm的五条线段中，任选三条可以构成三角形的概率是____%．
My grandmother is 70 years old,but she still writes____(诗).
绿色开花植物的结构层次不包括（ ）
