问题
单项选择题
一对夫妻色觉正常,他们的父母也均正常,但妻子的弟弟患色盲。则这对夫妻生一个色盲儿子的几率是()
A.0
B.1/2
C.1/4
D.1/8
答案
参考答案:D
一对夫妻色觉正常,他们的父母也均正常,但妻子的弟弟患色盲。则这对夫妻生一个色盲儿子的几率是()
A.0
B.1/2
C.1/4
D.1/8
参考答案:D
选择方框中的单词或词组填空,使句子完整。 | |
2. The sign means we should stay ____________ the building. 3. Nancy is going to play the piano ____________. 4. Do more exercise, and you'll get ____________. 5. It' s warm ____________ in spring in New York. 6. In spring, the weather gets ____________ and the trees turn green. |