They are sure they have all the facts they need to ______ the existence of a black hole.A．

What happens after the kids have had all the sweets？A．They get highly energetic.B．They qui

听力原文：（A) They are having a rally race. （B) All men come from the same team. （C) This i

Why do travel specialists have the most up-to-date information？A．They are all the local pe

They are sweating all over. They ______ in the field.A．may beB．must have been workingC．cou

They all agreed that the changes that have taken

They all agreed that the changes that have taken