Directions: Complete the sentences with the expressions below. Change the form where necessary.at once go hand in hand let go of most of all show up1. Among all the challenges in learning a new language, grammar rules are tricky, but ________, vocabulary acquisition is the hardest part for most students.2. During the experiment, even minor errors in the data will ________ under the microscope, making it easy for researchers to identify and correct them.3. In modern workplaces, multitasking requires employees to handle several urgent tasks ________, which can be overwhelming without proper time management.4. After a difficult breakup, it's important to ________ negative emotions and focus on personal growth for a healthier future.5. In sustainable development, economic growth and environmental protection must ________.

我们来逐题分析并完成句子填空。题目要求使用下面的短语，并在必要时改变形式：

提供的短语有：

• at once
• go hand in hand
• let go of
• most of all
• show up

第1题：
句子： Among all the challenges in learning a new language, grammar rules are tricky, but ______, vocabulary acquisition is the hardest part for most students.

分析：
这句话的意思是：“在学习新语言的所有挑战中，语法规则很难，但最重要的是，词汇积累对大多数学生来说是最难的部分。”
前后句之间是递进关系，强调“最困难的是词汇”。
“most of all” 表示“最重要的是，尤其是”，符合语境。

答案： most of all

完整句子：
Among all the challenges in learning a new language, grammar rules are tricky, but most of all, vocabulary acquisition is the hardest part for most students.

第2题：
句子： During the experiment, even minor errors in the data will ______ under the microscope, making it easy for researchers to identify and correct them.

分析：
句意是：“在实验中，即使数据中的微小错误也会在显微镜下____，使研究人员容易发现并纠正。”
这里需要一个动词短语，表示“显现、出现”。
“show up” 意为“出现，显现”，符合语境。
主语是“errors”，用一般将来时“will show up”。

答案： show up

完整句子：
During the experiment, even minor errors in the data will show up under the microscope, making it easy for researchers to identify and correct them.

第3题：
句子： In modern workplaces, multitasking requires employees to handle several urgent tasks ______, which can be overwhelming without proper time management.

分析：
句意是：“在现代职场中，多任务处理要求员工______处理多个紧急任务，如果没有良好的时间管理，这可能令人不堪重负。”
这里强调“同时处理多个任务”，“at once” 意为“同时，立刻”，符合语境。

答案： at once

完整句子：
In modern workplaces, multitasking requires employees to handle several urgent tasks at once, which can be overwhelming without proper time management.

第4题：
句子： After a difficult breakup, it's important to ______ negative emotions and focus on personal growth for a healthier future.

分析：
句意是：“在一段艰难的分手后，重要的是要______负面情绪，专注于个人成长，以拥有更健康未来。”
这里需要一个动词短语，表示“放下、释放”。
“let go of” 意为“释放，放下（情感、过去等）”，符合语境。
结构是“to let go of negative emotions”，不定式作主语补足语。

答案： let go of

完整句子：
After a difficult breakup, it's important to let go of negative emotions and focus on personal growth for a healthier future.

第5题：
句子： In sustainable development, economic growth and environmental protection must ______.

分析：
句意是：“在可持续发展中，经济增长和环境保护必须____。”
这里表达的是两者相辅相成、密不可分的关系。
“go hand in hand” 是固定搭配，意为“相伴而行，密切相关”，常用于表达两个事物必须同时存在或发展。

答案： go hand in hand

完整句子：
In sustainable development, economic growth and environmental protection must go hand in hand.

最终答案：

1. most of all
2. show up
3. at once
4. let go of
5. go hand in hand

\boxed{
\begin{aligned}&1.\ \text{most of all} \\&2.\ \text{show up} \\&3.\ \text{at once} \\&4.\ \text{let go of} \\&5.\ \text{go hand in hand}\end{aligned}
}