语法填空    阅读下面短文，在空白处填人一个适当的词，或填人括号中所给单词的正确形式

Plenty of people dream of going to Mars（火星）．____ different from those people, 13-year-old Alyssa Carson has been working ____ 　(happy) for that dream since the age of 4，according to a new report which ____ 　(make) by the BBC not long ago.

    Alytsa tells the BBC,“I hope____ (go) to Mars because it is a place that no one has been to before. I want to take that first step.” According to the BBC, she____  (attend) USA's three world space camps so far.

    Her father, Bert Carson, tells the BBC that Alyssa plans to be on the first long journey to Mars which is expected to take place in____ year of 2033.“We are proud ____  her,”he says.“We have the next eighteen____ (year) planned out.”One of those plans is Alyssa attending the International Space University.

Of course，Alyssa's dream could come with____  (big) sacrifices（牺牲）than others.[If Alyssa goes to mars，maybe ____ is very difficult for her to return to Earth. Still，her father says，"If that's the only choice she has，she still wants to go.”Alyssa agrees.