（1）He wants to be a scientist by his endeavor.
（2）Please research the medicine carefully.
（3）Yesterday i sent some photos to my parents.
（4）At the begining of this semester,i found that math is very difficult.1.虽然下雨，但他们继续在工作2.他们将怎样实现梦想3.我喜欢历史，但语文不适合我4.下周我能来看你5.他的你能否做此事表示怀疑Though it rains,they continue to work.How they will achieve their dream?I like history,but Chinese is not suitable for me.I can visit you next week.第五题真心看不懂你要表达什么意思啊，是不是打错字了啊？

1. 妈妈许诺给我买钢琴

2. 人们很难坚持到底

3. 这个题太难而无法面对回答

My mon promises that buy an piano for me.It is difficult for people to stick out.The problem is too difficult to answer.