实验室正在测试这些模拟物是否能产生与咖啡因相同的提神效果。

The lab is testing whether these ___simulants can produce the same alertness effects as caffeine.

实验室使用这些模拟物来模仿火星岩石的特性。

The lab uses these ___simulants to mimic the properties of Martian rocks.