例 一个初级精母细胞在减数分裂的第一次分裂时，有一对同源染色体不发生分离，所形成的次级精母细胞减数分裂的第二次分裂正常；另一个初级精母
He was puzzled by this phenomenon．He began to try every approach the best way of working it out． A．known finding B．knowing to find C．known to find D．know
______ the Internet is of great help, I don’t think it’s a good idea to spend too much time on it.A. If B. Bacause C. While D. As
下列命题中正确的是A.若a,b,c成等差数列，则a2,b2,c2成等差数列B.若a,b,c成等差数列，则log2a,log2b,log2c成等差数列C.若a,b,c成等差数列，则a+2,b+2,c+2成等差数
《文献通考卷二十四·国用考二》说：“今中书主民，枢密院主兵，三司主财务，不相知。财已匮而枢密院益兵不已，民已困而三司取财不已。中书视民
某同学用实验的方法探究影响单摆周期的因素. (1)他组装单摆时,在摆线上端的悬点处,用一块开有狭缝的橡皮夹牢摆线,再用铁架台的铁夹将橡皮夹紧,如
若函数f(x)=x3-f′(-1)x2+x+5,则f′(-1)= .
Which is_____ to learn skating or swimming? A．easy B．easier C．easily D．more easily
