学渣刚碰SQL，学了几个礼拜，却仍不会做练习！只会简单SELECT, FROM, WHERE...  跪求求大神帮忙，万分感激！！！

1.1:SELECT e.ename
FROM employees e
INNER JOIN certified c ON e.eid = c.eid
INNER JOIN aircraft a ON c.aid = a.aid
WHERE a.aname ='boeing aircraft';
1.2:SELECT c.eid
FROM certified c
WHERE c.aid IN(SELECT a.aid FROM aircraft a WHERE a.cruisingrange = MAX(a.cruisingrange));
1.3:SELECT e.ename
FROM employees e
WHERE e.salary < (MIN(REAL) FROM flight f WHERE f.from ='losangeles' AND f.to =' honolulu' );