Choose a subordinating conjunction to combine each pair of simple sentences. 选择合适的连词连接每一题中的两个句子。 Sleep patterns change during teenage. Any parent of a teenager can prove.

Choose a subordinating conjunction to combine each pair of simple sentences. 选择合适的连词连接每一题中的两个句子。 Computers work accurately and at high speeds. They save research workers years of hard work.

Choose a subordinating conjunction to combine each pair of simple sentences. 选择合适的连词连接每一题中的两个句子。 The number of school bus casualty is not large. The safety of children is always of intense public concern.

Choose a subordinating conjunction to combine each pair of simple sentences. 选择合适的连词连接每一题中的两个句子。 A child’s daydreaming is hindering him/her from progressing in school or from gaining social        skills. There is no need to discourage it.

Choose a coordinating conjunction to combine each pair of simple sentences. 选择合适的并列连词连接每一题中的两句。 Hotel guests have their meals free. They naturally go to the free dining rooms to have their meals.