1．(2020·新高考全国卷Ⅰ)In the 18th and 19th centuries, wealthy (wealth) people travelled and collected plants, historical objects and works of art.
2．(2020·全国卷Ⅰ)Landing on the moon's far side is extremely (extreme) challenging.
3．(2020·全国卷Ⅱ)Certainly (certain) during the holiday period, this plant is a must.
4．(2020·全国卷Ⅱ)The beautiful (beauty) long branches covered with pinkcolored buds (蓓蕾) make fantastic decorations.
5．(2020·全国卷Ⅲ)One day the emperor wanted to get his portrait (画像) done so he called all great artists to come and present their finest (fine) work, so that he could choose the best.
6．(2020·全国卷Ⅲ)As the small boat moved gently (gentle) along the river he was left speechless by the mountains being silently reflected in the water.
7．(2019·全国卷Ⅰ)It is difficult to figure out a global population of polar bears as much of the range has been poorly (poor) studied; however, biologists calculate that there are about 20，00025，000 polar bears worldwide.
