Mark was a student at this university from 1999 to 2003, he studied very hard and wasmade Chairman of the Students’ Union[ ]

依次填入下列各句横线处的成语，最恰当的一项是(　　)(1)测试埃博拉药物和疫苗需要对照测试，过程漫长，而今埃博拉病毒肆虐，再________可能会延误时机，造成更多的患者死亡。(2)夏利曾经是中国最好的汽车品牌，如今却为生存发愁。这一事实道出了商业丛林法则：不思进取就会落后，________就要完蛋。(3)如今是一个科学技术爆炸的时代，科技的更新日新月异，一个民族如果缺乏接受新事物的勇气，________ ，终将被时代淘汰。

Jerry has promised to keep the secret, so he won’t tell anyone even though ______.

use another method to solve thisproblem, you’ll probably ______ it

My friend’s flight had taken off _________ I got tothe airport to see him off.