New words：

investment [ɪnˈvestmənt] n.投资；投入；投资额；投资物

必记高频搭配

make an investment (in sth)（在某事上进行投资 / 投入）
She decided to make an investment in her English learning.

investment in sth（对某物的投资 / 投入）
Our school’s investment in new books makes the library better.

investment of...的投资
Your investment of time in study will bring good grades.

New words：

invest [ɪnˈvest] v.投资；投入（时间 / 精力 / 心血）

核心语义围绕 “把钱 / 时间 / 精力投入到某事物中，以求回报” 展开。

必记高频搭配

We should invest more time in our English study.
You need to invest more time in practicing English.
Many people want to invest in the stock market for more income.

stock [stɒk] n.股票

New words：

submerge /səbˈmɜːrdʒ/ v.沉没；使…淹没；把…浸入；从视线中消失

Sample Sentences：

He submerged his hands in the cold water to cool down.
The diver submerged and looked for fish in the deep sea.

New words：

emergency [ɪˈmɜrdʒənsi] n.突发事件；紧急情况；急诊

Sample Sentences：

We should keep calm in an emergency.
Call 120 at once if an emergency happens.
110 is the emergency call for police in China.
The doctor left quickly because of a medical emergency.

New words：

emerge /ɪˈmɜːrdʒ/ v.出现；浮现；显现；暴露；露出真相

同源联动记忆：

把emerge（v.出现） 和emergency（n.紧急情况） 绑定记忆
突然出现的（emerge）危险状况就是紧急情况（emergency），一次记两个词，效率翻倍。

必记高频搭配

emerge from...（从…… 中出现 / 浮现 / 走出）
The sun emerged from the clouds after the rain.
The children emerged from the forest and ran towards us.

The truth finally emerged after a long investigation.

investigation /ɪnˌvestɪˈɡeɪʃn/ n.调查；侦查；科学研究；学术研究