要原因（ ）In order to keep healthy,you____to do enough exercise

要原因
（ ）In order to keep healthy,you____to do enough exercise and have a good diet
A ought B can C must D should
( )Nothing can be done___our captain gives an order and we have to wait right now
A because B as C after D unless
( )When they first came to China,none of them could ____ a word of Chinese
A say B speak C tell D talk
Nuclear radiation is very dangerous.It may hurt or kill thousands of people nearly（合并为一句）
Nuclear radiation is dangerous______ _______hurt or kill thousands of people nearby.