某单位全体员工在植树节义务植树240棵．原计划每小时植树a棵．实际每小时比原计划的多植树10棵，那么实际比原计划提前了( )（用含a的代数式表示）．
单词拼写。（5分
小题1:E________ people are hardly ever tired.
小题2:Without my p_________, don’t touch my things
小题3:You must pay a___________ to your spelling.
小题4:She s__________ in getting a place at art school.
小题5:Raining often is the f___________ of the weather in the south.
健康父母产下一个视网膜母细胞瘤的孩子，则其余子女患此病的风险大约是（）
A.12％
B.10％
C.6％
D.15％
E.1％
