急性细菌性咽-扁桃体炎有别于其他上呼吸道感染的突出表现是()。
A.起病急
B.发热
C.咽痛明显
D.鼻粘膜充血肿胀
E.颌下淋巴结肿大
参考答案:C
Measures have been taken to prevent accidents, but much ______ for more improvement.
A.remains to be done
B.is remained to do
C.remains to do
D.is remained to be done
已知(2x-1)+i=y-(3-y)i,其中x,y∈R,求x=______,y=______.