Answer:
Mammals first appeared
Explanation:
The dinosaurs became extinct one million years after the Cenozoic era started. The mammals first appeared as the modern culture first appeared in that era.
Barbiturates are drugs that act as depressants on the central nervous system. They have a wide effect range, which means, the drugs can cause mild to total anesthesia effects. If the effectiveness of a barbiturate as a sedative depends on its ability to penetrate the non polar membrane of the cell, then based on this fact, hexethal will be more effective. This is because, it is more non polar than barbital; hexetal has a helxyl gruoup instead of the ethyl group present in the barbital.
U.s energy information office
The laboratory is full of chemicals and other hazardous substances. So, it is very important to keep all the safety precautions before entering in the laboratory to avoid any mis-happening.
Here are some precautions, which one should take before entering lab:
- Before entering the laboratory one must wear all the safety equipment including gloves, goggles, apron, and others.
- Make sure you are not wearing any inflammable thing and you are fully covered, as in some laboratory, harmful radiation are also present.
- Make sure your hair are tied in properly and the shoes are covered.