无损探伤检验是对焊缝内在质量的检验,其具体手段有( )。
A.射线探伤
B.超声波探伤
C.磁粉探伤
D.气密性检验
参考答案:A,B,C
— Mum, I am sorry, but I failed in the English exam.
— So you ________ get the MP4 you want. I am sorry, too. [ ]
A. shall not
B. might not
C. needn't
D. shouldn't
流行性腮腺炎的病理特征是
A.腮腺的急性化脓性炎症B.腮腺的急性非化脓性炎症C.非化脓性胰腺炎D.睾丸炎或卵巢炎E.病毒性脑膜炎或脑膜脑炎