1: People have developed many different paper products 2:He asked us many difficult question 3:They must widen the road soon 4:She advised me to reuse milk bottles 5:My sister cleans these rooms everyday 6:Wastes have caused a lot of pollution 7:When does he usually do his homework? 8:My father planted this tree 9:He hasn^t collected the rubbish 10:Are people using recycled paper ? Dạng bị động