题干

豌豆中高茎(T)对矮茎(t)为显性,绿豆荚(G)对黄豆荚(g)为显性,以上两对基因自由组合。则Ttgg与TtGg杂交后代的基因型和表现型的种类依次是

A:5种和3种

B:6种和4种

C:8种和6种

D:9种和4种

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B

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    Our “Mommy and Me” time began two years ago. My next-door neighbor and fellow mother, Christie, and I were out in our front yards, watching seven children of age 6 and under ride the bikes up and down. “I wish I could take one of my children out alone,” said Christie.

    Then we worked out a plan: When Christie takes one of her children out, I'll watch her other three. And when she watches two of mine. I'll take someone out.

    The children were extremely quick to accept the idea of “Mommy and Me” time. Christie's daughter, McKenzie, went first. When she returned, the other children showered her with tons of questions. McKenzie was smiling broadly. Christie looked refreshed and happy. “She's like a different child when there's no one else around,” Christie shared with me quickly. With her mother all to herself, McKenzie didn't have to make an effort to gain attention.

    Just as Christie had noticed changes in McKenzie, I also discovered something different in each of my children. For example, I am always surprised when my daughter, who is seldom close to me, holds my hand frequently. My stuttering (口吃的) son, Tom, doesn't stutter once during our activities since he doesn't have to struggle for a chance to speak. And another son, Sam, who's always a follower when around other children shines as a leader during our times together.

    The “Mommy and Me” time allows us to be simply alone and away with each child-talking, sharing, and laughing, which has been the biggest gain. Every child deserves to be an only child at least once in a while.