根据句子意思,用所给单词的适当形式填空.

题目

根据句子意思,用所给单词的适当形式填空.
71 Their parents are both teachers And_(I) are doctors.
72.You can make a_(decide) among the suggestions.
73.THe law of gravity_(discover)by Isaac Newton about 350 scars ago.
74.He lives on the__(nineteen ) floor of the building.
75.We had better eat more_(harm ) vegetables.
76____(luck）all of them were hurt in the accident.
77.1 am going to the USA to have a_(far) study.
78 The Great Wall as well as the palace museum__(attract)lots of tourists from abroad every year.
79.We should do everything we can_(protect)the environment.
80.By 5:30yesterday afternoon he_(ftnish)writing the laboratory report.

答案

71.mine指代我的父母
72.decision make a decision固定搭配做决定
73.was discovered被发现
74.nineteenth序数词第十九层
75.harmful 形容词,有害的
76.unluckily不幸的是
77.further比较级,表示程度上
78.attracts谓语用单数
79.to protect不定式表目的
80.had finished by＋过去时间用过去完成时