public GameObject smallEnemy; // 小敌机预制体
float createSmallSpeed = 1f; // 小敌机生成速度
Vector3 pos = this.transform.position;
pos = new Vector3(Random.Range(-2.7f, 2.7f), pos.y, pos.z);
Instantiate(smallEnemy, pos, Quaternion.identity);
InvokeRepeating("CreateEmeny", 0.1f, createSmallSpeed);