The fact that the insects living on these plants died out ____ produced less food supply for birds and wolves.A. in return B. in place C. in turn
蚕豆根尖细胞在含3H标记的胸腺嘧啶脱氧核苷培养基中完成一个细胞周期,然后在不含放射性标记的培养基中继续分裂至中期,其染色体的放射性标记分
青篙素(化学式为 C15H22O5)是治疗疟疾的特效药,关于青篙素的说法正确的是( ) A.青篙素中含有42个原子 B. 青篙素
After a 5-minute discussion, we came up with a better ____ to the math problem. A. access B. way C. approach D. aspect
右图为KNO3和NaCl两种物质的溶解度曲线。 (1)两种物质的溶解度受温度的影响变化较大的是_______。 (2)t1℃时,两种物质溶解度的大小关系为KNO3___ _
医生建议患甲状腺肿大的病人多食海带等海产品,这是因为海带中含有较丰富的( ) A.氟元素 B.碘元素 C.锌元素 D.钙元素
----_______ I tell the head teacher all that has happened? ----No, you _______! Mr. Xin would be terribly angry. A. Will; needn’t B. Would; can C. Should; mustn’tD. Must; don’t have to