[题目]下列关于胡萝卜素的叙述.错误的是( )A．胡萝卜素可用于治疗幼儿生长发育不良.干皮症等B．胡萝卜素可从大面积养殖的岩藻中提取C．萃取过程中要采用水浴加热D．提取胡萝卜素时.可采用石油醚.苯.丙酮等作溶剂题目和参考答案——青夏教育精英家教网—

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【题目】下列关于胡萝卜素的叙述，错误的是（）

A．胡萝卜素可用于治疗幼儿生长发育不良、干皮症等

B．胡萝卜素可从大面积养殖的岩藻中提取

C．萃取过程中要采用水浴加热

D．提取胡萝卜素时，可采用石油醚、苯、丙酮等作溶剂

【答案】D

【解析】胡萝卜素可以用来治疗因缺乏维生素A而引起的各种疾病，如夜盲症、幼儿生长发育不良、干皮症等；工业生产上，提取天然β—胡萝卜素的方法主要有三种，一是从植物中提取，二是从大面积养殖的岩藻中获得，三是利用微生物的发酵生产；萃取过程中需要避免明火加热，采用水浴加热，这是因为有机溶剂是易燃物，直接使用明火加热容易引起燃烧；提取胡萝卜素时，对于溶剂的要求为具较高沸点、能够充分溶解胡萝卜素且不与水混溶，此外还要考虑萃取效率、对人的毒性等，由于苯和丙酮均对人体有害。综上所述，石油醚是理想的溶剂。故D正确。

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WISDOM MISSION SCHOOL ADMISSION PROCEDURE

FOR JR. HIGH/HIGH SCHOOL STUDENTS

Thank you for choosing Wisdom Mission School for your child’s future. We are committed to provide quality education with love.

Prospective US residents are welcome to apply for admission by submitting the following documents via e-mail, fax, and US mail to Wisdom Mission School:

Wisdom Mission School

Admission Office

5851 Newman St.

Cypress, CA 90630

Phone: 1－714－995－1900 1－562－833－2070

Fax: 1－714－995－1910

E-mail: wms.edu@gmail.com

Required Documents for Jr. High/High School Students (Click to Download Forms)

Admission Application

Student Agreement (Rules and Regulations)

Transcript (Sent directly by previous school)

Essay on the reason for Admission to Wisdom Mission School

After you submit all the documents, admission is approved.

Enrollment Agreement along with Tuition/Fees Payment.

	Elementary (K—6th)	Jr. High (7th—8th)	High (9th—12th)
Tuition	$450×11 Payments	$540×11(Honors) $900×10(Regular)	$9,000 or $900×10 Payments
Enrollment Fee	$600($300/2nd child, $200/3rd child)		$700
Other Fee	None		$500
Re-registration Fee	Paid by April 1st: $100 Paid after April 1st: $150		None

【1】What do students have to get from their previous school?

A. Transcript. B. Student agreement.

C. Essay. D. Admission application.

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A. fax to 1－714－995－1910

B. finish the enrollment agreement along with Tuition/Fee Payment

C. click to download forms

D. complete the forms

【3】How much is the Enrollment Fee if one couple has three children, and two will go to Elementary and another will attend High in Wisdom Mission School?

A. $1,100. B. $1,300. C. $1,600. D. $1,800.

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