Famous________a writer, Lu Xun is well known________Chinese people________his wonderful works. A．like; for; as B．for; to; as C．as; to; for D．to; as; for
用秋水仙素处理二倍体西瓜幼苗获得四倍体植株。则( ) A．四倍体西瓜植株与二倍体西瓜植株属于同一物种 B．四倍体植株与二倍体植株不存在生殖隔离
如果 –1，a，b，c，– 9成等比数列，那么（ ） A．b = 3，ac = 9 B．b = –3，ac = 9 C．b = 3，ac = –9 D．b = –3，ac = –9
为进一步确定来源不同的A、B、C、D、E五种物质（或结构）的具体类型，进行了下列实验，现象与结果如下表： ①各种物质（或结构）的性质、染
阅读下列名片，完成短文，每空词数不限。 ________is always ready to tutor you in reading，math and science．Pat Ridley is a good teacher for people who want to learn English
常用氯气给自来水消毒。某学生用自来水配制下列物质的溶液，不会产生明显药品变质的是（ ） A.石蕊 B.硝酸银
The Science of Risk-Seeking Sometimes we decide that a little unnecessary danger is worth it because when we weigh the risk and the reward, the risk seems worth tasking. 91 _ Some of us enjo
下列式子中（其中的a、b、c为平面向量），正确的是 （ ） A．
______时，代数式
与
的值互为相反数
