根据所给单词的首字母, 完成下列句子 （共10小题；每小题1分，满分10分）
小题1:The boy felt u________ because he didn’t do well in the exam.
小题2:Don’t let your dog l_______ if there are any sheep around.
小题3:Before the c_________ went up, the dancers took their places on the stage.
小题4:The hotline helps many t__________ who are growing up.
小题5:After a few days of fever, he began to r_________.
小题6:Chinese is the o_________ language of China.
小题7:I will have to increase my ___________(词汇量)
小题8:He speaks English f________, for he has stayed in England for quite a long time.
小题9:It took four years to plan the _____________（航行）
小题10:The police soon established his true i__________ and he was quickly found.
小题1:upset
小题2:loose
小题3:curtain(s)
小题4:teenagers
小题5:recover
小题6:official
小题7:vocabulary
小题8:fluently
小题9:voyage
小题10:identity
小题1:upset失望，沮丧，形容词形式。
小题2:loose疏松的，没加束缚的。Let sb. do让某人做，注意用动词原形形式。
小题3:curtain(s)幕，幕布，可用复数形式。
小题4:teenagers青少年，注意前面的many，故用复数形式。
小题5:recover恢复，注意前面的不定式to，故用动词原形形式。
小题6:official官方的，需要注意用形容词形式。
小题7:vocabulary词汇量，注意用名词形式。
小题8:fluently流利地，注意修饰动词，故用副词形式。
小题9:voyage航行，注意用名词形式。
小题10:identity身份，这里为名词形式。