心瓣膜病最常累及的瓣膜是
A. 主动脉瓣和三尖瓣
B. 二尖瓣和主动脉瓣
C. 三尖瓣和肺动脉瓣
D. 二尖瓣和三尖瓣
Listen carefully and choose consonant cluster you hear.
A. / tr/
B. /ts/
C. /dr/
D. /dz /
Listen carefully and choose the word you hear.
A. tents
B. tends
C. dents
D. fends
Listen carefully and choose the word you hear.
A. world’s
B. worst
C. words
D. waits