慢性白血病首选的药物是()。
A.白消安
B.羟基脲
C.靛玉红
D.α-干扰素
E.环磷酰胺
参考答案:B
. For miles around us there was nothing but a desert, without a single plant or tree ______.
A.in the distance
B.at a distance
C.in sight
D.out of sight
I don’t think one can keep healthy ______ taking enough exercise. [ ]
A. with
B. without
C. for
D. to