____the doctors in their hospital is about one thousand, and sixty percent of them___________ women.
A:A number of; is
B:The number of; are
C:The number of; is
D:A number of; are
I can ____ ____ a ____now .
新____ ____ ____ 局____ ____ ____
绝____ ____ ____ 齐____ ____ ____
类____ ____ ____ 意____ ____ ____
若a2=3,b =2,且ab<0,则a-b=____ .
下列光学仪器中,成放大实像的是( )
做土壤渗水实验时,必须控制条件相同的是( )
①取用砂粒和黏粒的体积相同 ②加入的水量一定要相同 ③漏斗的形状要完全相同
④漏斗里放入的脱脂棉花要一样多 ⑤锥形瓶的大小应完全相同