金属壳雷管标注时，字码痕迹深度不应小于（）。

A、6μm

B、0.5mm

C、1mm

D、5mm

One day before my final exam, my dad gave me a gift. It completely changed my life.
On that day I had a (16) with my friends and it was a difficult time with my studies. I was unhappy. Then I noticed the gift. I (17) it and saw a DVD inside. Its name was "THE SECRET". However, I was in no mood(心情) to watch it. I sat down to study, but the (18) in my life—the fight, the sleepless nights and my poor health...Everything came to my mind. I wanted an answer but I wondered (19) there was any. Just then,I saw the DVD again. Maybe it would be helpful. I (20) my DVD player. I had no words to describe the feelings I experienced while watching it. The moving(动人的) stories of human beings made me so moved that I wouldn’t (21) any of them.
Thanks to my father’s gift "THE SECRET", I discovered (22) . Everybody has difficulties in their lives. The important thing is that you should be (23) enough to face them. Now I have started (24) my studies and my friends. And I’m in good health, too. I often hear people say, "Wow! (25) perfect life you have! \

Ⅱ. 完形填空/Cloze

A．why

B．that

C．if

D．how