在噬菌体侵染细菌的实验中，新噬菌体的蛋白质外壳是 A．在细菌的DNA的指导下，用细菌的物质合成的 B．在噬菌体的DNA的指导下，用噬菌体的物质合成
一个精原细胞和一个卵原细胞分别含有3对同源染色体，经减裂形成的生殖细胞的种类和数量分别为：
实验室制取CO2应选择的装置是（ ） A．①③ B．②③ C．②④ D．②⑤
When you hear the word quicksand, what image comes to mind? You probably picture someone up to the waist in wet land, screaming for help. In fact, quicksand can be very dangerous. People and animal
They lived a hard life then, for their father _______ for half a year. A. had lost his work B. has lost his work C. had been out of work D. has been out of work
（本小题满分13分） 已知椭圆（a＞b＞0）的焦距为4，且与椭圆有相同的离心率，斜率为k的直线l经过点M（0，1），与椭圆C交于不同两点A、B．
下列运算正确的是A．2m3＋m3＝3m6B．m3·m2＝m6C．(－m4)3＝m7D．m6÷2m2＝m4
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。 The organization
