以下哪种法可用来确定某种矿质元素是否是植物所必需的（） A.比

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问题单项选择题

以下哪种法可用来确定某种矿质元素是否是植物所必需的（）

A.比较老叶和嫩叶中某矿质元素的含量

B.分析土壤中某矿质元素的含量

C.分析影响某矿质元素吸收的因素有哪些

D.观察舍全部营养的培养液中去掉某矿质元素前后植物的生长发育状况

答案

参考答案：D

补全对话，情景问答

看图读对话，选择符合图意的对话，将其序号填入图下括号内。

( ) ( ) ( ) ( )

1. A: What time do you get up?

B: At six o'clock.

A: Does your brother get up earlier than you ?

B: No. He gets up later.

2. A: When is your birthday?

B: It's on the first of July.

A: Would you like a puppet as a birthday present ?

B: Yes, please.

3. A: Let's go to the park.

B: Good idea. But how do we go there ?

A: Let's go on foot.

B: All right. Let's go.

4. A: Excuse me, can you tell me the way to the toilet ?

B: Go along this street, and then turn right at the first crossing. The toilet is on your right. You can't miss it.

A: Thank you very much.

B: You're welcome.

选择题

A．按规定停放车辆

B．不随意丢弃废电池

C．回收使用过的塑料、橡胶

D．在绿化带堆放杂物