测煤灰熔融性时，当温度达900℃后，升温速度应为（）℃／min。
A.7±1；
B.5±1；
C.10±1；
D.15～20。
参考答案：B
Look at the pride on Tom's face. He _____ to have been praised by the manager just now. [ ]
A. seemed
B. seems
C. had seemed
D. is seeming
洋地黄中毒最常见的心电图表现是ST-T呈鱼钩样改变。
