（6分）据图回答下列问题：

（1）据图1，若某植物幼苗已表现出向光性，且测得其向光面的生长素浓度为m，则背光面生长素浓度范围是             。
（2）据图1可知，除草剂灭草的原理是使杂草的生长素浓度大于       （填图1中字母）。
（3）在探究生长素促进插条生根的最适浓度时，一名技术人员用几种不同浓度生长素溶液处理插条基部，然后在沙床中培养，观察生根情况。图2为生长素促进枝条生根的情况。请结合图1判断，在下列各项浓度值中，最好选用（   ）

A．3mg·mL-1

B．6 mg·mL-1

C．9 mg·mL-1

D．4.5 mg·mL-1

（4）生长素的主要作用是促进细胞纵向伸长，其作用机理如图3所示，请回答下列问题：

①生长素作用的第一步是与细胞膜上的受体结合，形成“激素—受体复合物”，这一过程体现了细胞膜的              功能。
②实验发现，细胞在持续生长过程中，细胞壁将发生一定变化，出现这种现象的原因是由于              （填细胞器）为细胞壁添加了新的成分。
③此外，Ca²⁺ 还能激活细胞中的转录因子，它进入细胞核后，能引起         酶催化mRNA的合成。

—Would you like to play tennis with me _________ it doesn’t rain tomorrow?

  —Sure, _________ I am busy.

A. if; since         B. whether; but    C. if; unless             D. because; until

 

Hi, my name is Wang Jun. Do you want to know about my staying in America? Well, to tell you the truth, it is really an eye-opening experience here.
In China, I had English classes five times a week since Grade Five. But I didn’t know textbook English could be so different from everyday English until I came to Hotchkiss School, Connecticut. When I first studied English, I was told to say “I’m fine.” when people say “How are you?” But in the USA, I found that people say “I’m good.” or “I’m tired.”
One day, someone greeted （问候） me with “What’s up?” It made me confused. I thought for a moment and then smiled because I didn’t know what to say.
Since then, I have learnt more and more differences between Chinese and American cultures. To my surprise, American girls spend a lot of time in the burning sun getting a tan (晒黑的肤色). In China, girls try every possible way to keep their skin white.
American students are hard-working like Chinese students. In China, schoolwork is almost everything, so we study hard and that’s it. But here, a “good” student not only gets good grades, but also does a lot for the public. That is to say, they get lots of knowledge at school and learn many life skills from social （社会的） work.
【小题1】In China, Wang Jun had _______ English classes every week.

A．five

B．four

C．three

D．two

【小题2】Wang Jun found that _______ when he came to Hotchkiss School in the USA.
A. it was really important to learn English well
B. English he learnt in China was helpful to him
C. American students were more hard-working than Chinese students
D. textbook English was different from everyday English
【小题3】What does the underlined word “confused” mean in Chinese?

A．困惑的

B．滑稽的

C．紧张的

D．伤心的

【小题4】American girls make Wang Jun feel surprised because _______.

A．they work hard at school	B．they try to keep their skin white
C．they hope to get a tan	D．they do lots of social work

【小题5】Which of the following is the best title for the passage?

A．My wonderful travel in the USA	B．After-school activities in American schools
C．What American students learn at school	D．My study experience in the USA

--Your Japanese is so good. How long have you been in Japan?

-- __________ I was five.

A．Since             B．Before            C．Until             D．When