Small sailboats can easily turn over in the water ________.

Small sailboats can easily turn over
small sailboats can easily turn over in the water if not managed carefully
翻译 尤其是turn over

求下面7道英语题的答案、急、
1、small sailboats can easily turn over in the water,____they are not managed carefully.
A.though B.before C.until D.if
2.___he referred to in his article was unknown to the general reader.
A.That B.What C.Whether D.Where
3.the traditional view is ___we sleep because our brain is "prgrammed" to make us do so.
A.when B.why C.whether D.that
4.it is difficult for us to learn a lesson in life___we've actually had that lesson.
A.until B.after C.since D.when
5.choosing the right dictionary depends on___you want to use it for.
A.what B.why C.how D.whether
6.last week,only two people came to look at the house ,___wanted to buy it .
a.none of them b.both of them c.none of whom d.neither of whom
7.many of them turned a deaf ear to his advise,___yhey knew it to be valuable.
a.as if b.noe that c.even though d.so that