An occasional loose sentence prevents the style from becoming too formal and allows the reader to relax slightly.
偶尔的松散句子可以防止风格变得过于正式，让读者稍微放松一下。
RA真题机经真⼈示范
Loose sentences are common in easy, unforced writing, but it is a fault when there are too many of them.
松散的句子在轻松、自然的写作中很常见，但是当它们太多时就是一个错误。
英语百科
Loose sentence
A loose sentence (also called a cumulative sentence) is a type of sentence in which the main idea (independent clause) is elaborated by the successive addition of modifying clauses or phrases.
近义、反义、联想词
近义词
n.
complex sentence
英英词典
loose sentence n.
a complex sentence in which the main clause comes first and the subordinate clause follows