题目: 下列对“克隆”概念认识的叙述,不正确的是()A.由单个细菌长成菌落,属于个体水平克隆B.PCR技术属于分子水平克隆C.植物组织培养技术也属于克隆技术D.淋巴细胞与骨髓瘤细胞融合成杂交瘤细胞属于细胞水平克隆 答案: 参考答案:D
题型:完形填空 完形填空。 Beautiful pictures of mountains and forests, clear skies, flying birds, wild animals, silly faces - you can find them all in one place. 1 ? On a postcard! Have people always sent postcards? No! Before postcards, people 2 sealed (密封的) letters. The 3 for the first decorated (装饰的) postcard came to John P. Charlton in 1861. He thought a simple card 4 a border would be a great way to send a note. Then in the late 1800s, postcards which had pictureson them 5 . By law, people had to write their note on the front-on the picture! The back was 6 for the address. Several years later, England allowed a divided-back (背面隔开的) postcard. Then people could writetheir 7 on the back left side. And they put the address 8 . During the early 1900s, the golden age of postcards, people around the world were more and more 9 picture postcards. In 1908, Americans alone mailed over 677 million postcards. Today, postcards are the 10 most popular collection in the world after stamps and coins. You can alwayssee or get a lot of newly-designed postcards, especially on New Year's Day. ( )1. A. How ( )2. A. liked ( )3. A. advice ( )4. A. above ( )5. A. happened ( )6. A. even ( )7. A. note ( )8. A. on the front ( )9. A. surprised at ( )10. A. first B. When B. hated B. picture B. with B. changed B. only B. word B. on the back B. interested in B. second C. Why C. found C. idea C. under C. ended C. still C. address C. on the left C. expected by C. third D. Where D. lost D. card D. for D. appeared D. ever D. letter D. on the right D. worried about D. fourth 查看答案
题型:单项选择题 某施工项目某月的成本数据如下表所示。错误的是()。A.预算成本增加对成本降低额的影响是1.2万元B.成本降低率提高对成本降低额的影响是5.46万元C.实际的成本降低额是15.36万元D.预算成本和成本降低率对成本降低额的影响是6.96万元 查看答案
题型:问答题 简答题 计算题:用ICP-AES分析样品时,分析线Cr205.55nm受到Fe的干扰。当溶液中Fe的度为1000mg/L时,造成Cr浓度增加0.2mg/L,求Fe对Cr的干扰系数。 查看答案