TPO62_L2_Encounter of Galaxies part 1

When a massive star reaches the end of its existence, it explodes. What is the meaning of 'reach' in this context?

• 触碰
• 达到
• 延伸
• 到达

Which then fades to invisibility within a few weeks or months. What does 'fades' mean here?

• 变色
• 渐渐消失
• 减弱
• 消散

Which then fades to invisibility within a few weeks or months. In this sentence, what does 'invisibility' mean?

• 透明
• 无形
• 隐形
• 不可见

When a massive star reaches the end of its existence, it explodes. What does 'explode' mean in this context?

• 扩张
• 爆炸
• 破裂
• 爆发

That process emits a distinctive type of radiation. What is the meaning of 'emit' in this sentence?

• 发射
• 辐射
• 释放
• 放弃

The same type of radiation has been observed in places where galaxies have collided. What does 'collided' mean here?

• 碰撞
• 连接
• 合并
• 交叉

Usually in clusters. In this sentence, what does 'cluster' refer to?

• 巨大的

• 星团
• 集合
• 类别

Excited hydrogen gas has been found in the regions where the two galaxies overlap. What does 'region' mean in this context?

• 地下

• 地带

• 区域
• 范围

It looks like the ripples in a pond after a stone has been tossed in. What is the meaning of 'ripples' in this sentence?

• 涟漪
• 波纹
• 波动
• 褶皱

Most of what we theorize about comes from computer simulations. What does 'simulation' mean here?

• 模仿
• 模拟
• 演练
• 仿真