问题
选择题
It is a good idea to ask for a map at the information center,_____ may prove to be very useful,
Before you start your tour of the museum. [ ]
A. where
B. which
C. who
D. that
答案
答案:B
It is a good idea to ask for a map at the information center,_____ may prove to be very useful,
Before you start your tour of the museum. [ ]
A. where
B. which
C. who
D. that
答案:B
对下列实验指定容器中的水,其解释没有体现水的主要作用的是 ( )
A | B | C | D | |
实 验 装 置 | ![]() 硫在氧气中燃烧 | ![]() 测定空气中氧气含量 | ![]() 铁丝在氧气中燃烧 | ![]() 排水法收集氢气 |
解释 | 集气瓶中的水: 吸收放出的热量 | 量筒中的水: 通过水体积的变化得出O2体积 | 集气瓶中的水: 冷却溅落融熔物,防止集气瓶炸裂 | 集气瓶中的水: 水先将集气瓶内的空气排净,后便于观察H2何时收集满 |