【单选题】The Internet is made up of an incredibly large number of independently operated ____________.
【单选题】下列说法正确的有 [ ]
A.
将某精原细胞的DNA用 15 N标记后转入 14 N的培养基中培养,若进行减数分裂形成四个精子细胞,则所有细胞均含有 15 N
B.
受精卵中的遗传物质一半来自父方,一半来自母方
C.
用基因型为DdTt的植株进行单倍体育种,所育的种自交后代约有1/6为纯合体
【单选题】进行开塞露治疗的作用机制是
A.
A.使黏膜渗透压增加,使电解质和水向肠腔渗透@@B.@@C.@@D.@@E.
【简答题】Fill in the blanks with words or phrases in Reading A 1. The Internet is made readily to the staff who work from home. 2. The lack of self-discipline and self-confidence much of the failure of persona...
【单选题】下列说法中,完全正确的组合是 ①将某精原细胞的DNA用 15 N标记后转入含 14 N的培养基中培养,若进行减数分裂形成四个精细胞,则所有的DNA均含有 15 N ②受精卵中的遗传物质一半来自父方,一半来自母方 ③用基因型为DdTt的植株进行单倍体育种,所育的种自交后代约有1/16为纯合体 ④细菌分裂生殖时,导致子代之间差异的可能原因是基因突变和染色体变异 ⑤生物个体发育过程是细胞内不同基因有序表...
【单选题】The Internet is made up of many networks. It's like a big supermarket.
【单选题】10个月男婴,诊断为重症支气管肺炎伴急性心力衰竭。你首先准备使用的药物是