降负荷过程中除氧器的液位（）。
A.上升
B.下降
C.不变
D.不确定
参考答案：B
_____going to the shop and buy some toys? [ ]
A. What about
B. Why not
C. Would you like
D. Why don't you
血清人绒毛膜促性腺激素（HCG）增高见于（）
A.肝癌
B.卵巢癌
C.乳腺癌
D.恶性葡萄胎
E.睾丸肿瘤
