对下面文段中所使用的修辞方法的作用理解正确的一项是（   ）

①一年三季，花开花落，没有间歇；莺歌燕舞，变化亦多。②然而，在一墙之隔的大门内，夹竹桃却在那里悄悄地一声不响，一朵花败了，又开出一朵，一嘟噜花黄了，又长出一嘟噜。③在和煦的春风里，在盛夏的暴雨里，在深秋的清冷里，看不出它什么特别茂盛的时候，也看不出什么特别衰败的时候，如温润的少女，无日不迎风含笑，从春天一直到秋天，从迎春花一直到玉簪花和菊花，无不奉陪。④这一点韧性，同院子里那些花比起来，不是显得非常可贵吗？  

A．①句运用对偶的修辞手法，绘出了三季百花次第竞放、色彩斑斓的绚丽景象，语言凝练，意蕴丰富。

B．②句赋予花以人的情态，写出了夹竹桃不与百花争艳，“一声不响”坚持默默开放的态势，表现了夹竹桃的胆小懦弱及少女温润而执着的个性。

C．③句运用排比、比喻和拟人的修辞手法，突出了夹竹桃无论环境如何，始终如一的坚韧品格和少女般张扬而不屈服的个性。

D．④句运用反问的修辞手法，有力地突出了夹竹桃韧性品格的可贵，表达了作者对夹竹桃的赞美之情。

阅读下面短文，根据上下文填入适当的词语，或使用括号中的词语的适当形式填空。

     Foreign students are valuable to the United States. Many take 1_____ in important research. Most have

to 2_____ the full costs for their education. That helps universities meet their budgets. International students

and their 3_____ put 12,000 million dollars into the American economy last year. That number is from the

Institute of International Education, based in New York.

     Now, many education officials say they are concerned that 4_____ students will come to the United States

for the next school year. The officials base their concern partly on a decrease in students 5_____ (plan) to

attend intensive English programs during the summer.

     The members said one reason 6_____ the expected decrease is slower and more restrictive United States

action on travel documents. 7_____ (secure) has increased since the terrorist attack of September 11,2001.

The schools also blamed the travel problems caused by the outbreak of SARS.

     In recent years, 8_____ increasing number of students have come to the United States to study. The

Institute of International Education says these students represent more than four percent of all students in

American colleges and universities. 9_____ says the number of international students reached a 10_____ high

of more than 580,000 last year. The largest number came from India. Before last year largest number came

from China.