【单选题】下列说法正确的是 [ ]
D.
葫芦藓的吸水能力很强,所以生有葫芦藓的地方比较潮湿
【单选题】准确称取0.4000 g硅酸盐试样,经碱熔、浸取、凝聚、过滤、灼烧得含杂质的SiO 2 0.2800 g,再经HF-H 2 SO 4 处理后,称得残渣量0.0018 g,则试样中SiO 2 的质量分数为:
【单选题】液相色谱中,固定相极性大于流动相极性属于
【判断题】所有的藻类植物都是单细胞的,都生活在水中。
【判断题】Ingeneral, to explain the sources of the information is the first step when we writethe letter in order to establish the business relationship.
【单选题】what is the first step when a volunteer recives a suicide call?
A.
check the proper boxes
C.
give the caller suggestion
D.
do not know how to deal with
【单选题】What does the woman mean? A.They have plenty of drinks. B.They need another refrigerator. C.They need to buy some more drinks.
【单选题】树的度为3,且有9个度为3的结点,20个叶子结点,但没有度为1的结点。则该树中度为2的结点数为()