An earthquake comes like a thief in the night, without warning.

like a thief in the night ^{不期而至/不知不觉；偷偷摸摸（习语）secretly or unexpectedly and without being seen} 

• The years, like a thief in the night, have stolen what you were.
• Innocence slipped away from me like a thief in the night.
• The sudden market crash comes like a thief in the night, surprising everyone.^{突然的市场崩盘不期而至，让所有人都感到意外。}
• Illness can sometimes come like a thief in the night, rapidly changing one's life.^{疾病有时会像夜间的盗贼一样到来，迅速改变一个人的生活。}
• The unexpected heavy snowstorm came like a thief in the night, paralyzing the city.^{这场突如其来的大暴雪不期而至，使城市陷入瘫痪。}

without warning ^{suddenly and with no signs that it was going to happen, used about bad or dangerous things （贬义） 突然，突如其来地;没有警告/毫无预兆}

• He blazed up without warning. 
• Then, without warning, her husband left her.
• The system failed without warning, causing massive data loss.^{系统在毫无预兆的情况下失败了，导致大规模数据丢失。}
• The animal attacked the hunter without warning.^{那只动物毫无预兆地袭击了猎人。}

It was necessary, therefore, to invent instruments that neither slumbered nor slept.

therefore ^{adv.因此/所以(不特别强调“因果”关系，多做插入语，用于补充说明)}

• There is still much to discuss. We shall, therefore, return to this item at our next meeting.
• Progress so far has been very good. We are, therefore, confident that the work will be completed on time.
• The road was slick with ice; therefore, we drove cautiously.^{道路上结了一层冰；因此，我们小心翼翼地开车。}
• She missed the deadline for the application; therefore, her request was denied.^{她错过了申请截止日期；因此，她的请求被拒绝了。}

instrument ^{1. 乐器}

• We have an old musical instrument.

instrument ^{2. 仪器，设备}

• His telescopic observations are justly immortal; they aroused great interest at the time, they had important theoretical consequences, and they provided a striking demonstration of the potentialities hidden in instruments and apparatus.

slumber ^{v. (fml.) sleep, esp. peacefully and comfortably 睡眠（尤指睡得安稳而舒服）}

• The baby was slumbering peacefully.

neither slumbered nor slept ^{既不打盹也不睡觉/时刻保持警醒（同义词连用，表强调，如：“深仇大恨、美丽动人、拖拖拉拉...”）}

• The security system was designed to neither slumber nor sleep, monitoring 24/7.^{该安全系统被设计成时刻保持警醒，进行24/7的监控。}
• In times of crisis, the emergency team must neither slumber nor sleep until the threat is neutralized.^{在危机时期，应急小组必须时刻保持警醒，直到威胁被消除。}

Some devices were quite simple.

quite simple ^相当简单

• The instructions for assembling the furniture were quite simple.^{组装家具的说明相当简单。}
• The solution to the complex problem turned out to be quite simple.^{这个复杂问题的解决方案结果是相当简单。}

One, for instance, consisted of rods of various lengths and thicknesses which would stand up on end like ninepins.

on end ^{1. upright 直立，竖着}

• He placed the box on end and sat on it.
• The reader’s hair stands on end when he reads in the final pages of the novel …

on end ^{2. continuously 连续地}

• They argued for two hours on end.
• Some plays are so successful that they run for years on end.

ninepins ^{n. [U] a game in which you roll a ball at nine bottle-shaped objects to try to hit them so that they fall 九柱戏}

• The pillars were placed close together, standing up on end like ninepins.^{柱子被紧密地放置在一起，像九柱戏的木瓶一样立着。}
• to fall down or become ill / sick in great numbers ^{大量倒下；大批病倒}

consisted of ^{由…组成/构成}

• The original menu only consisted of five items.^{最初的菜单只由五道菜组成。}
• The exhibit hall mainly consisted of interactive displays and video screens.^{这个展厅主要由互动展示和视频屏幕构成。}

When a shock came, it shook the rigid table upon which these stood.

upon which (Formal Structure) ^{在其上（正式结构）}

• The foundation is the base upon which the entire structure rests.^{地基是整个结构立在其上的基础。}
• That decision was the turning point upon which his whole career hinged.^{那个决定是他的整个职业生涯所依赖的转折点。}

If it were gentle, only the more unstable rods fell. If it were severe, they all fell. ^{主真从虚（混合使用）教程视频第19分处}

If it were gentle/severe  ^{如果是轻微的/严重的（虚拟语气）}

• If it were I, I would choose the more challenging option.^{如果是我，我会选择更具挑战性的选项。}

Demographers expect it to take decades for China’s birth rate to recover ― by which time China may have become the first country in history to have grown old before growing rich. ^{(The Economist)}

Thus the rods, by falling, and by the direction in which they fell, recorded for the slumbering scientist the strength of a shock that was too weak to waken him, and the direction from which it came.

in … direction ^向…方向

• Tony glanced in her direction and their eyes met.
• The girls pointed in the opposite direction.

from … direction ^从…方向

• There was a loud scream from the direction of the children's pool.