陕西省部分县2021-2022学年高二下学期期末考试英语试题汇编：七选五

陕西省部分县 2021-2022学年高二下学期期末考试英语试题解析版汇编 七选五 陕西省富平县2021-2022学年高二下学期期末质量检测英语试题 第二节（共5小题，每小题2分，满分10分） 根据短文内容，从短文后的选项中选出能填入空白处的最佳选项，选项中有两项为多余选项。 Four Rules for Successful Plant Cloning Plant growers have two choices when it comes to starting new plants: growing from seed, or plant cloning. And plant clones offer advantages that growing plants from seed can’t offer. Growing from clones, you’re sure to have all females, and as long as you do the cloning yourself, you know who the mother plant is and how your clones will grow, yield, and get you high. ___16___. Take your plant cuttings from a healthy mother plant Plant cloning gives you genetic copies of your mother plant. ___17___, your clones get the best start possibly. Avoid using mother plants that are sick, or that are plagued with pests. ___18___ Most plant clones prefer temperatures slightly higher than your ideal grow room temperature, and they don’t like a day and night cycle with a temperature drop at night. That’s why most growers root their cuttings under lighting that stays on 24 hours a day. The lighting itself creates temperature stabilization. Temperatures between 74 — 77 degrees Fahrenheit are the range you want. Clones like high humidity Your cuttings need a humid environment in the 75 — 95% humidity range until they’ve created roots and are able to intake water through them. That’s why many plant cloners use humidity covers. You need to wait your clones have functioning roots. ___19___, they’ll die. Use sterile equipment and materials You already figured out that your scissors, knife or other tools for cutting clones has to be clean. But you also want to make sure you trays, cloning covers, and root zone media are clean and sterile too. ___20___. Start fresh every time. When you follow these plant cloning tips, your clone success rate should be nearly 100%. A. If they’re in dry air B. Use kind LED lighting C. Give your plant clones consistent climate D. But it’s an art and science to plant cloning E. Don