—What are you doing?
—I am _________ a letter.[ ]
A. write
B. writing
C. writes
答案:B
判定下列何项正确()
A.心腔和大血管在T1和T2加权像上均呈黑影
B.空气和骨皮质含氢量少,磁共振信号弱
C.空气和骨皮质无论在T1或,T2加权像上均为黑色
D.以上全正确
E.以上全不正确
包裹bāo ɡuǒ