A train crosses 650m long bridge and 800m long platform in 20sec and 30 sec respectively. what is speed of train?​

What are igneous intrusions and extrusions

The mini-refrigerator fire was most likely caused by what type of wiring?

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid