【单选题】Although many factors affect human health during periods in space, weightlessness is the dominant and single most important one. The direct and indirect effects of weightlessness lead to a series of r...
【简答题】Complete the following dialogues with the words in the box. enjoy, sports, would, strength, often, spend, 1. A: So what’s your favorite ? B: I usually play football on Wednesday. A: Why do you like fo...
【简答题】Almost everyone considers going on a diet sometime in his or her life. All, regardless of and age, have something in common- -losing weight and losing it fast. Though their common aim may seem bas...