【单选题】I don't want to ______sc hool. [ ]
【单选题】下列有关有机化合物的性质或结构或用途的说法正确的是
A.
蛋白质和油脂都属于高分子化合物,一定条件下都能水解
C.
乙醇既可以作燃料,也可以在日常生活中使用,如无水乙醇经常用于医疗上杀菌、消毒。
D.
蛋白质溶液中分别加入饱和(NH 4 ) 2 SO 4 和CuSO 4 溶液,均有沉淀,原理不相同
【单选题】下列说法正确的是( )
A.
蛋白质属于天然高分子化合物,组成元素只有C、H、O、N
B.
用浓Na 2 SO 4 、CuSO 4 溶液或浓HNO 3 溶液使蛋清液发生盐析,进而分离、提纯蛋白质
C.
蛋白酶是蛋白质,它不仅可以催化蛋白质的水解反应,还可以催化淀粉的水解反应
D.
甘氨酸(H 2 N-CH 2 -COOH)既有酸性,又有碱性,是最简单的氨基酸
【简答题】阅读理解。 Dear Cindy, How's going with you? For me it's terrible. Three are too many rules in our school. It isn't fair. I have to get up at five forty every morning. I can't be late for running, I have ...
【单选题】Ice Hotel Sweden Sweden's Ice Hotel, first constructed in the late 1980's, is built from scratch every year. A new design, new suites, a brand new reception—in fact everything in it is crisp and new. ...
【判断题】固定窗 是 不能开启的窗, 一般将玻璃直接装在窗框上,尺寸可较大。特点:构造简单,制作方便。用途:只能用作通风或装饰。
【简答题】交际运用。根据对话内容及方框中所给的句子补全对话。其中有一项是多余的。 A: Have you ever been late for school? B: Hardly ever. only once or twice every term. 1 A: Have you ever overslept? B: Yes, I have. A: 2 B: I would ask my father to...
【简答题】完成句子。 1. 如果你起床晚,你将会上学迟到。 ______ you ______ ______ late, you'll ______ ______ for school. 2. 如果他们在聚会上看录像,会发生什么情况? ______ ______ ______ if they ______ a video at the party? 3. —什么时间举办这个聚会最好? —你要是有空就今天吧。...
【判断题】固定窗是指一般在窗框上直接镶玻璃或将窗扇固定在窗框上不能开启的窗。通常用于走道、楼梯间的采光窗和一般窗的某些部位。