题目

如图是某种遗传病的系谱图．基因B对b为一对等位基因，假设6号个体不带致病基因，请分析回答： （1）该遗传病最可能是     染色体上的      （显性或隐性）基因决定的． （2）8号是杂合体的几率是           ． 答案：（1）性X      隐性 （2）用所给词的适当形式填空。1. My family _____ (decorate) our house before Christmas every year.2. We _____ (celebrate) Christmas with a family meal.3. I _____ (send) some Christmas E-card to my friends last year and I _____ (be) really happy to _____    (make) a contribution to the environment protection.4. People always _____ (sing) Traditional Christmas songs at Christmas.5. My mother with my little sister usually _____ (go) shopping before Christmas. 6. My classmate, Xiao Ming, never _____ (go) to the parks on weekends. She just _____ (do)     homework. She _____ (study) hard. But I _____ (not agree) with her. I _____ (think) she'd better    _____ (have) a rest after hard work.7. Mike _____ (not feel) well. He _____ (feel) sick, and his parents _____ (look) worried.