Which complex sentence is written correctly?    

Choose the compound sentence.

What is the subordinating conjunction in the following sentence? “I do not understand technology; life was much simpler before computers and smart phones came into our lives.”  

Reflect on the course in general.  What did you like best?  Least?  How can the course be improved?  (Note: there is no correct or incorrect answer here.)

At which phase of the Moon do Solar eclipses occur?

If the source of the wave is moving towards the observer, the wavelength of the emitted wave

One characteristic of Venus, which distinguishes it from the other planets, is

Which of the following statements is correct about the surface temperature of the following stars? 

We have evidence that the Earth’s magnetic field has reversed its direction over long periods of time

Which of the following is a consequence of the fact that the rotation and revolution periods of the moon are the same (synchronous rotation)?