题型：问答题 简答题 完形填空。 Hello, my name is Jack. I like sports. I have a good friend. 1 name is Mary Black. 2 is her familyname. She also likes 3 . I have a basketball. We play 4 basketball in the afternoon. Mary 5 some ping-pong balls and I have ping-pong bats. We play ping-pong every day and we are in the ping-pong clubof the school. ( )1.A. His ( )2.A. Mary ( )3.A. food ( )4.A. a ( )5.A. has B. She B. Black B. sports B. an B. plays C. He C. Mary Black C. English C. the C. watches D. Her D. Jack D. fruit D. \ D. looks 查看答案
题型：问答题 简答题 已知4个连锁基因的交换值分别是：A和B为40%，B和C为20%，C和D为10%，C和A为20%，D和B为10%。下图中能正确表达这4个基因位置关系的是[ ]A．B．C．D． 查看答案
