天然形成的玻璃必须冠以“()”二字。
参考答案:天然
— Our class won the English speaking contest.
— Congratulations! You _____ be very proud of it. [ ]
A. can
B. need
C. would
D. must
肾绞痛和肾外伤及其并发症的首选检查方式为()
A.CT
B.MRI
C.B超
D.KUB
E.IVU