韧皮部中含有起输导作用的是[ ]
A.导管
B.筛管
C.髓
D.形成层
答案:B
—All of us are proud of the progress he's made during the past few years.
—Yes, we're sure he will be even _____. [ ]
A. successful
B. more successful
C. most successful
D. successfully
泪液分泌减少或其成分异常可引起干眼症,可采用______试验或检查______。