The sun is heavier than the Earth.(改为一般疑问句) Dr Zhang works in the space station.(改为一般疑问句) Dr Zhang has a rest [in the eveing].(对括号部分提问) There is gravity inthe space station.(改为否定句) There is a sunrise or sunset [every 45 minutes].(对括号部分提问)
Is the sun heavior than the Earth? Does Dr. Zhang work in the space statiom? When does Dr. Zhang have a rest? There isn't gravity in the space station. How often is a sunrise or sunset?