SG 科学命令词解码器

Q: State two symptoms of diabetes. [2]

✓ Good: Frequent urination and excessive thirst.

✗ Poor: Diabetes makes people drink a lot of water and feel tired sometimes, and they also need to use the toilet very often...太啰嗦：State 题不要解释、不要展开。

Q: List three civilisations in which the early symptoms of diabetes were recorded. [3]

✓ Good: Egyptian, Indian, Chinese.

✗ Poor: Egyptian, Indian, Chinese, Arabic, Greek ...题目要 3 个就给 3 个，多写不加分还可能因前 3 个错而扣。

Q: Define the term qualitative data. [1]

✓ Good: Observations that describe an object or phenomenon using the senses, usually expressed in words or drawings.

✗ Poor: It's the kind of data that doesn't have numbers, like when you say a coconut is green and hard.过于口语；定义要保留关键术语（senses, describe）。

Q: A student wants to find the height of a coconut. State one piece of equipment she could use to measure it. [1]

✓ Good: A metre rule (or measuring tape).

✗ Poor: She estimates it by looking.Estimate ≠ Measure。Measure 必须涉及仪器。

Q: Describe Aretaeus' contribution to understanding diabetes. [2]

✓ Good: He coined the term diabetes (meaning "siphon" or "passing through") to describe the excessive urine produced by diabetic patients.

✗ Poor: He was a Greek doctor who discovered diabetes.太笼统；Describe 要说出他做了什么（具体动作）。

Q: Outline how scientists design a fair test. [2]

✓ Good: Change one variable at a time (independent), measure its effect on another (dependent), and keep all other variables constant.

✗ Poor: 把整个实验方法写一页 ...Outline 不是 Describe —— 不要细到 every step。

Q: Sketch a graph showing the height of a child over the first 10 years of life. Label both axes. [3]

✓ Good: 平滑曲线 · 开始陡 · 后段缓 · 不过原点（婴儿身高 ≠ 0）· 横轴 "Age (years)" · 纵轴 "Height (cm)"

✗ Poor: 一根直线 · 没有坐标轴标签 · 从 0 开始关键特征（曲线形状、起点不为 0）和标签都失分。

Q: Comment on the value of the scientific method in everyday life. [2]

✓ Good: It allows decisions to be based on evidence rather than opinion. For example, choosing an effective medicine requires controlled testing, not personal belief.

✗ Poor: Science is very important.没有具体点；[2] 至少要两个独立要点。

Q: Explain why Copernicus's heliocentric model was not immediately accepted. [3]

✓ Good: Because evidence is interpreted against strongly held assumptions; the community had assumed for over a thousand years that Earth was the centre, so it took time for new evidence to accumulate and shift this assumption.

✗ Poor: Because people didn't believe him.没有机制。Explain 要说"为什么会这样"的因果链。

Q: Discuss the role of the scientific community in deciding what counts as scientific knowledge. [4]

✓ Good: The community accumulates and scrutinises evidence collectively, which filters out individual bias. However, this can be slow — Copernicus's heliocentric idea took decades to gain acceptance even after observable evidence existed.

✗ Poor: The community is very important because they decide what is true.只说一面；Discuss 必须有支持 + 反对/局限的张力。

Q: What do you understand by the term evidence-based? [2]

✓ Good: A claim is supported by observations or experimental data rather than personal opinion or tradition. In science this is the requirement for any theory to be accepted.

✗ Poor: It means based on evidence.只复述了字面；要给定义 + 在科学里为什么重要。

Q: A coconut has a mass of 1.5 kg. Calculate its weight on Earth. (g = 10 N/kg) [2]

✓ Good: Weight = mass × g = 1.5 × 10 = 15 N.

✗ Poor: 15缺单位、缺公式 —— 即使数字对，可能只拿 1/2 分。

Q: Determine the density of a coconut shell. Mass = 50 g, volume = 40 cm³. [2]

✓ Good: Density = mass ÷ volume = 50 ÷ 40 = 1.25 g/cm³.

✗ Poor: 1.25没公式、没单位。Determine 是 Calculate 的"间接版"，要求更严。

Q: A pedometer recorded 8500 steps. If average step length is 0.7 m, find the total distance walked. [2]

✓ Good: Distance = 8500 × 0.7 = 5950 m (or 5.95 km).

✗ Poor: 5950缺单位。

Q: Estimate the number of times your heart beats in one day. Show your reasoning. [3]

✓ Good: Assume average heart rate ≈ 75 bpm. 75 × 60 min × 24 h ≈ 108 000 beats per day.

✗ Poor: About a million.没显示推理。Estimate 要把假设写出来才有分。

Q: Suggest one reason why marine biologists sometimes use computer programmes to study marine organisms virtually. [1]

✓ Good: To avoid disturbing or harming the organisms in their natural habitat. (任何一个合理理由都行)

✗ Poor: 留白 / "I don't know."Suggest 题不答必失分。猜一个合理的就行。

Q: A scientist found that part of the brain regulates blood sugar level. Deduce what might happen if that brain region were damaged. [2]

✓ Good: Blood sugar regulation would be impaired, possibly leading to abnormally high or low blood sugar levels.

✗ Poor: The person would be ill.太笼统 —— 没有从题目给的信息（脑→血糖）推出。

Q: Compare qualitative and quantitative data. [2]

✓ Good: Qualitative data uses the senses to describe characteristics (e.g., colour, texture), whereas quantitative data uses instruments to give numerical measurements (e.g., 500 g, 2 cm).

✗ Poor: Qualitative uses senses. Quantitative uses numbers.各说一句不算 Compare。必须有 whereas/while 把两者绑在一起。

Q: Classify each as qualitative or quantitative data: (a) leaf colour, (b) water temperature 28 °C, (c) flower fragrance, (d) apple mass 160 g. [4]

✓ Good: (a) qualitative · (b) quantitative · (c) qualitative · (d) quantitative.

✗ Poor: 只答了 a 和 b。必须把每一项都分类 —— 漏一项失一分。

Q: Construct a balanced equation for the combustion of methane (CH₄) in oxygen. [2]

✓ Good: CH₄ + 2 O₂ → CO₂ + 2 H₂O

✗ Poor: CH₄ + O₂ → CO₂ + H₂O没平衡（左边 2 H，右边 2 H 但 4 O vs 2 O）。Construct 题不平衡 = 0 分。