It's snowing tonight. I am afraid . [ ]
A. To driving
B. drive
C. to drive
D. driving
答案:C
氨是重要的无机产品之一,在国民经济中占有重要地位。下列表述中正确的是 [ ]
A.氨的电子式为
B.NH3(l)=NH3(g);△H<0
C.在2NH3+NaClO=N2H4+NaCl+H2O中,氨是还原剂
D.氨溶于重水:NH3+D2ONH2D2++OH-
子宫内膜异位症最典型的症状是:
A.痛经和持续下腹痛
B.不孕症
C.月经过多
D.白带增多
E.继发性闭经