下列物质,哪种不能由乙烯直接合成()。
A、乙酸;
B、乙醇;
C、乙醛;
D、合成塑料。
参考答案:D
一青年人,肺门淋巴结肿大,PPD试验5U,硬结直径15mm,伴水泡,诊断为
A.结核病B.结节病C.淋巴瘤D.肺癌E.矽肺
---- What do you think of zoology?
---- In my opinion, zoology is ______ botany.
A.a subject so interesting as
B.as a interesting subject as
C.as interesting a subject as
D.interesting as a subject as