阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

    My name is Billy Smith. I'm 50 years old this year. I was about 440 pounds two years ago. ____(fortunate), I managed to lose weight.

    I began to gain weight when my mom developed Parkinson's disease in 1994. I soon became her caregiver, and continued to provide her ____ care for over 10 years. But when the pressure of taking care of my mother and ____(keep) my job got too much for me, I began to skip meals and feed on fast food. I gained weight quickly.

    My huge weight gain caused me to develop high blood pressure. I also had ____(difficult) in breathing at times. In 2014 I went to see my doctor,____ told me that I would die within two years if I didn't lose weight. This wasn't what I expected. I wanted to see my young son grow up, and I knew it was time to make a change.

    I started to eat healthy food and work out in the gym. Finally, I ____(succeed) in losing weight. Now I weigh just 260 pounds. I had never been to my son's Parents' Meeting ____ I was so ashamed and ____(scare) that my weight would lead to him being laughed at. Now ,____ (look) normal, I can do the things I have never been able to do,____should have done as his father.

在遗传学上，相对性状是指：同种____、同一性状的不同表现形式．