Living in _______ ever increasingly fast-paced world, we are facing greater competition, so we must take _______ advantage of every opportunity to develop. A. an; the B. an; 不填 C. the; an D. the; 不填 答案:B下列各项中表达正确的是
A.F的结构示意图:
B.CO2的分子结构式:O=C=O
C.NaCl的电子式:
D、N2的结构式: :N≡N: