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.