关于我的暑假的英语作文

observance n. A traditional form or customary act.
observant adj. Quick to notice.
observatory n. A building designed for systematic astronomical observations.
obsolescence n. The condition or process of gradually falling into disuse.
obsolescent adj. Passing out of use, as a word.
obsolete adj. No longer practiced or accepted.
obstetrician n. A practitioner of midwifery.
obstetrics n. The branch of medical science concerned with the treatment and care of
women during pregnancy.
obstinacy n. Stubborn adherence to opinion, arising from conceit or the desire to have
one's own way.
obstreperous adj. Boisterous.
obstruct v. To fill with impediments so as to prevent passage, either wholly or in part.
obstruction n. Hindrance.
obtrude v. To be pushed or to push oneself into undue prominence.
obtrusive adj. Tending to be pushed or to push oneself into undue prominence.
obvert v