Which of these advances did Han scientists make? Select all that apply. A: developed the concept of zero
B: devised the base-20 number system
C: created more accurate calendars
D: invented the compass
PLZ HELP QUICK IM DOING THE TEST RN

What was a goal of the treaty of versailles? to germany rebuild its industry to build better roads and factories in germany to make sure germany did not invade france in the future to give great britain and the united states credit for their in wwi