単語チェック

There was a festive atmosphere in the Japan Sport Olympic Square — which sits just across the street from National Stadium 

・sit across～：～の向かいに座る

The run-up to the Tokyo Games was filled with concern about the ongoing pandemic, various scandals and a public that seemed vehemently opposed to holding the games as scheduled.

・run-up：準備期間
・vehemently（víːəməntli）：熱烈に
・vehemently oppose to～：～に強烈に反対する

Across the street from the main venue on the day the Games officially arrived, however, a crowd gathered to take in whatever part of the experience they could — perhaps a testament to the popularity of the Olympics even in times of strife — taking photos with the Olympic rings and each other.

・testament：証拠 
・strife：衝突、対立

Even though the crowd was a stone’s throw away from National Stadium, they were separated from the Games’ centerpiece venue by a fence that served as a reminder of the distance at which the Tokyo Games will be kept from the citizens of the city hosting them.

・a stone's throw away from～：～からすぐ近く、～から目と鼻の先
・centerpiece：中心、最大の目玉

In an effort to promote diversity, the Tokyo Games marked the first time each nation was invited to select both a male and female flag bearer to carry the flag and lead their delegation into the stadium.

・delegation：代表団、委任

The Tokyo 2020 cauldron, a sphere designed with a sun motif that opens like a flower, is the first in Olympic history to be fueled by hydrogen.

・Olympic Cauldron：聖火台
・sphere：球体
・motif（moutíːf）：モチーフ
・hydrogen：水素
※燃料として、五輪史上初めて水素が活用されている。

The Games arrive on the heels of a buildup fraught with scandals and against the backdrop of a rising tide of COVID-19 cases in Tokyo.

・on the heels of～：～のすぐ後に続いて
・fraught（frɔt）：緊迫した
・backdrop：背景、状況
・rising tide：上昇時期

文法チェック

The Tokyo 2020 cauldron, a sphere designed with a sun motif that opens like a flower, is the first in Olympic history to be fueled by hydrogen.

短い文章であり、読めた方からすると平易な文章になります。しかし、正確に意味を把握しているのか？という点では要チェックな文章だとお思います。

主語と動詞を考えながら読むと、"The Tokyo 2020 cauldron（オリンピック聖火台）"が主語であり、"is"が動詞であることは目処が立ちます。

次に挿入部分について考えます。"a sphere designed with..."の箇所で"designed with..."以下の内容は"a sphere"を修飾しています。ここで、a sphereはcauldronの言い換えになっています。

つまり、挿入部分で聖火台について補足説明をしていることを"a sphere"を用いることで明確にしています。