使用圆盘锯锯短料时,料长不得小于锯片直径的( ),料高不得大于锯片直径的1/3。
A.1.5倍B.2.5倍C.2.0倍D.3.0倍
参考答案:A
阅读短文,用合适的单词填空。
Mr. Green is from England. He teaches English in a middle school. He speaks some Chinese, but only
a little. He goes to Chinese classes every week. He likes working in China very much. He says the
Chinese people are very kind to him. He has a son and a daughter. They go to school here, too. But
they go to a different school.
Mr. Green is ____ (1). He is a ____ (2) of English. He can speak some ____ (3), but ____ (4)
____ (5). He goes to Chinese classes every week. He likes working in China. He says the Chinese
people are very _____ (6). He has ____(7) ____(8). They go to school here. They ____ (9) in
different ____ (10).
用NA表示阿伏加德罗常数的值,下列叙述正确的是
A.在反应KIO3 + 6 HI=KI + 3I2+3 H2O中,每生成3mo1 I2转移的电子数为5NA
B.100mL 18.4mo1·L-1硫酸与足量Cu反应,生成SO2的分子数为0.92NA
C.1L 0.1 moI·L-1的CH3COOH溶液中所含的离子和分子总数为0.1NA
D.将0.lmol FeC13滴人沸水中可制得0.1NA Fe(OH)3胶粒