用在电路中的整流二极管，主要考虑两个参数_____和_____，选择时应适当留有余地。

二极管外加正向电压是呈现很大的电阻，而外加反向电压时呈现很小的电阻。

A. 对
B. 错

普通二极管在电路中正常工作时，其所承受的反向电压应小于二极管的反向击穿电压。否则会使二极管损坏。

A. 对
B. 错

straggle

A. to grow, spread or move in an untidy way in different directions
B. to use power or influence to affect somebody or something
C. to remove something off

crest

A. the middle part of a hill or wave
B. the top part of a hill or wave
C. the lower part of a hill or wave

lofty

A. very huge and clumsy
B. very deep and frightening
C. very high and expressive

soporific

A. making you want to vomit
B. making you want to sleep
C. making you want to cry

intrepid

A. very gentle
B. very cruel
C. very brave

abominable

A. very unpleasant or bad
B. very frightening
C. very aggressive

elusive

A. difficult to find, describe, remember, or achieve
B. not real, or imaginary in one’s mind
C. easy to deal with