3．Many kinds of plants and animals are extinct （灭绝）．The same thing ________ around the world．（ ）
| A． | happen | B． | happened | C． | is happening | D． | happens |
2．Be careful ________ the street when you are alone．（ ）
| A． | to cross | B． | with cross | C． | crossing | D． | of crossing |
19．A：Hey，Mom．Can I invite some friends to the party on Sunday afternoon？
B：（46）Sure，youcan．But you have to do some cleaning first．
A：What do I have to do？
B：Well，first you need to sweep the kitchen floor．
A：OK．（47）Thenwhat？B：Then you could take out the trash．
A：Yeah．（48）IcandothatB：And you need to clean your room．
A：Wow!I'm going to be too tired to go to my own party!
B：（49）I'llhelpyouI'll go to the store for drinks and snacks．
A：（50）Thanks，Mom
B：（46）Sure，youcan．But you have to do some cleaning first．
A：What do I have to do？
B：Well，first you need to sweep the kitchen floor．
A：OK．（47）Thenwhat？B：Then you could take out the trash．
A：Yeah．（48）IcandothatB：And you need to clean your room．
A：Wow!I'm going to be too tired to go to my own party!
B：（49）I'llhelpyouI'll go to the store for drinks and snacks．
A：（50）Thanks，Mom
| A．I'll help you． B．Then what？ C．Thanks，Mom． D．I'm busy now． E．I can do that． F．You're welcome． G．Sure，you can． |
18．I used to_____my dream．But now I get used to_____doing everything．I think I'll be successful one day．（ ）
0 122518 122526 122532 122536 122542 122544 122548 122554 122556 122562 122568 122572 122574 122578 122584 122586 122592 122596 122598 122602 122604 122608 122610 122612 122613 122614 122616 122617 122618 122620 122622 122626 122628 122632 122634 122638 122644 122646 122652 122656 122658 122662 122668 122674 122676 122682 122686 122688 122694 122698 122704 122712 159627
| A． | give up，keeping | B． | giving up，keeping | ||
| C． | giving up，keep | D． | give up，keep |