30.________ by a crowd of people, I felt nervous, ______ what to say. A．Watching, didn't know B．Having watched, and not knew C．Having been watch, not known D．Being watched, not knowing答案为D. 请问为什么不能用A

CRO是什么意思 cro是什么意思 cro是什么 请问：什么是CRO业务? CRO是什么组织? CRO 全程是什么 CRO是什么组织 英语翻译In 1799,George Washington in a letter witten only two days before his death,strongly urged the establishment of a military school.Three years later,the United States Military Academy opened with an enrollment of ten cadets.By 1902,the cro The boy ________ by his father is Tom A beaten B beatingThe boy ________ by his father is Tom A beaten B beating选A还是B?为什么 we ________ to work every day.a.by bus b.take a bus c.by air d.take a plane 3.They often begin their class ________ a song. A in B for C by Dwith 什么叫CRO企业着急 网优中的CRO是什么意思 the ground was ________ (cover) by a heavy fall of snow. The book was written ________ English.A.in B.with C.from D.by Do you come here ________ the car?A.on B.to C.by D.in He built a telescope ________ which he could study the skies 为什么不能用by I usually go to the office ________ train.A.with B.by C.on