In man's early days, competition with other creatures must have been critical.

man's early days ^人类早期

• In the pioneering days, however, this was not the case at all.
• In the early days of the settlement of Australia, enterprising settlers unwisely introduced the European rabbit.
• Man's early days were marked by constant struggle for survival against the elements.^{人类的早期以与自然元素的持续生存斗争为特征。}
• The artifacts offer a glimpse into man's early days and simple tools.^{这些文物提供了对人类早期和简单工具的一瞥。}

critical ^{adj. very important  重大的，关键的}

• Practice is a critical factor in learning English. ^做定语
• Financial support is critical to the region’s development.  ^做表语
• The unexpected weather event must have been critical to the failure of the harvest.^{意外的天气事件对收成失败来说必然是严峻的。}

But this phase of our development is now finished.

phase ^{n.阶段，期}

• Arthur C. Clark once suggested a revolutionary idea passes through three phases: …
• The wedding marked the beginning of a new phase in Emma's life. ^{婚礼标志着埃玛生活新阶段的开始。}
• The phase of writing that is actually most important is revision. ^{写作中真正最重要的阶段是修改。}
• We are entering a new era as this phase of our development comes to a close.^{随着我们发展的这个阶段接近尾声，我们正在进入一个新时代。}

Indeed, we lack practice and experience nowadays in dealing with primitive conditions. 

indeed ^{adv. used to introduce an additional statement that emphasizes or supports what you have just said 事实上；确实/实际上}

• I didn't mind at all. Indeed, I was pleased.
• It would be difficult. Indeed it would be almost impossible.
• The report confirms the initial findings; indeed, the results are even stronger than anticipated.^{报告证实了最初的发现；实际上，结果甚至比预期的还要强劲。}

I am sure that, without modern weapons, I would make a very poor show of disputing the ownership of a cave with a bear, and in this I do not think that I stand alone.

Without ^{代替if条件状语从句}

• Without something of this kind, searching for intelligences on other planets would be like trying to meet a friend in London without a pre-arranged rendezvous and absurdly wandering the streets in the hope of a chance encounter.

make a very poor show ^{出洋相 / 表现拙劣}

• The candidate made a very poor show during the interview. ^{那位应聘者在面试中表现得非常差劲。}
• It's a poor show if he forgets your birthday. ^{要是他忘了你的生日，那可太差劲了。}
• The juggler put up such a poor show on the music hall stage that he got the bird from the audience. ^{这个表演杂耍在音乐厅舞台上演得太差劲，因此被观众喝了倒彩。}
• Despite months of rehearsal, the lead actor made a very poor show of his final performance.^{尽管排练了数月，这位主角的最后一场演出表现得非常糟糕。}

stand alone ^{to be in a position or place where there are no other people 孤立}

• On this issue, Britain stands alone against the US. 
• So long as we stand together, we’ll win.
• Don’t stand there —give me a hand!
• He’ll be standing down as CEO at the end of the year.
• She is going to stand trial for tax evasion.
• No one is taller than those who are willing to stand corrected.

The Tibetans call it Chomulungma, “Goddess Mother of the Snows”. Goddess Mother of the world, actually. In the traditional Tibetan translation. I stand corrected. ^{我接受您的指正。}

• There is no need to stand on ceremony —come in and relax.
• If you want to go abroad, we won’t stand in your way.
• Facing the difficulty of learning a new language, I do not think that I stand alone.^{面对学习一门新语言的困难，我不认为我是一个人（有同感）。}

The last creature to compete with man was the mosquito.

the last creature ^{最后的生物(类指)}

• At last I found this amphibious creature. ^{最后我找到了这个两栖动物。}
• The extinction of the giant panda is a reminder that it may not be the last creature we lose.^{大熊猫的灭绝提醒我们，它可能不是我们失去的最后一个生物。}

But even the mosquito has been subdued by attention to drainage and by chemical sprays.

drainage ^{1. [U] process by which water or liquid waste is drained from an area 排水}

• a drainage system
• drainage facilities

drainage ^{2. [U] a system of drains 排水系统}

• The drainage of the city is not good: some of the pipes are broken.

spray ^{n. liquid which is forced out of a special container in a stream of very small drops 喷雾}

• a new hair styling spray
• Most farmers use pesticide sprays.

be subdued by ^{被…制服/征服}

• The sudden uprising has been subdued by the swift deployment of peacekeeping forces.^{突如其来的起义已被维和部队的快速部署所制服。}
• The spread of the invasive plant species has been subdued by the introduction of a natural predator.^{入侵植物物种的蔓延已被引入一种天然捕食者所制服。}