题干

如图表示某种农作物品种①和②培育出⑥的几种方法, 有关说法错误的是:

A:经过Ⅲ培育形成④常用的方法是花药离体培养

B:过程Ⅵ常用一定浓度的秋水仙素处理④的幼苗

C:由品种①直接形成⑤的过程必须经过基因突变

D:由品种①和②培育能稳定遗传的品种的最快途径是Ⅰ→Ⅴ

上一题 下一题 0.0难度 选择题 更新时间:2018-05-12 06:02:16

答案(点此获取答案解析)

D

同类题2

根据短文理解,选择正确答案。

Rafting the GRAND CANYON Welcomes You!

    For an exciting,fun and challenging white water tours,Rafting the GRAND CANYON is here to help you plan the right tour for you. Whether you want to travel for two days or ten,hike in or not,go on an oar raft or motorized trip,we will help you find the trip that meets your needs.

    For those who will be vacationing on the off­season a trip on the Native American Red River rafting is available year around or a one ­day trip is available on the Colorado River from Diamond Creek to Pierce Ferry (about three hours from Las Vegas).

    Most of the trips depart from Lees Ferry,Arizona (approximately 21/2 hours from the south rim of the Grand Canyon).We offer partial trips which allow you to get on or off at Phantom Ranch located at the bottom of the Grand Canyon National Park South Rim. Requiring a hike in or out,with proper planning the horse ride up or down is also an option. Most trips occur between April and October.

    Since all rafting on the Colorado requires a permit,planning and reserving your trip requires reservations well in advance. Please let us know when you would like to go and we will contact all the river concessionaires (特许权获得者)to help you find the best trip for you.

    For planning your trip,questions,concerns or to make your reservations,please email or call the toll free number below. Since these trips are limited we highly recommend you make your reservations months in advance.

    To talk to a live person call us toll free:1­800­222­6966 or 702­655­6060

    If you have any questions regarding a trip,please CLICK_HERE to fill out our form. This will speed up the process of getting you accurate information regarding your trip.

    If you would like to send us an email other than about an up­coming trip you can contact us at info@raftingthegrandcanyon.com.

    We look forward to helping you plan your trip! (Please NO Travel Agents)

同类题5


—Stay a bit longer , please. It’s been such ______ fun having you here .
—Thank you , but I’ve got ______ early start tomorrow morning .