共价键、离子键和范德华力是构成物质时粒子间的作用力。下列物质中,只含有上述一种作用力的是[ ]
A.干冰
B.NaCl
C.NaOH
D.I2
答案:B
Try to be more careful next time. Carelessness only ______ mistakes.
A.tends to
B.results from
C.leads to
D.turns to
幼儿教师的表达能力是教师口语。