【题目】_________ it was hard to keep up with the online classes, I tried my best to follow them.

【题目】The police ________ early on foot in order to find the truth behind the mystery.

【题目】There ________ no mountain on the earth that can grow taller than Qomolangma.

【题目】Our memories can ________ or even forgotten completely.

【题目】Wu Dajing broke his own record and _______the gold medal（奖牌）in the men's 500-meter race.

【题目】A friend of ________ named Paul received a new bicycle from his brother as a Christmas gift.

【题目】Our teacher always chooses classical songs she enjoys ________ us between classes.

【题目】If you live in Changchun, you may notice that the air in winter is not as _______as it is during the summer.

【题目】Knowledge can make________ difference in our life and change the world.

【题目】At 10 a.m. on April 4, 2020, people all over our country stood ________ of COVID-19.