47.
(A) pass
(B) passes
(C) passed
(D) passing

They have helped  pass laws to restrict smoking in public places. 

help可以當使役動詞,在 [a person + help another person ]的後面, 要用原型動詞或是不定詞,不能用Ving的形式

For example:

Lee is helping Dee carry the monkey.

Lee is helping Dee to carry the monkey.

Lee is helping Dee carrying the monkey.(錯誤)

這題不太能理解.....為什麼不用Passing ?.........

somebody help me ,please....!!

Many people do not smoke and do not like smoking. These nonsmokers are very [46]concernedabout the bad effects on people’s health from smoking. They have helped [47] pass laws to restrict smoking in public places. Nonsmokers believe that the smoke from other people can also hurt them. This is true. Scientists also believe that “second-hand smoke,” the smoke that nonsmokers breathe in from smokers, is very [48]dangerous. Because of this, many restaurants and offices in the United States and Canada limit the places where people can smoke. Many airlines and hotels do not [49] permitsmoking at all. Things are changing. People want to stay healthy and live better lives. It is not easy to quit smoking, but it is the smartest thing to do. If you quit smoking, your chance of getting lung cancer decreases within one year after you stop. After ten years, the chance is [50]almostthe same as for nonsmokers. It is possible to quit smoking. You can start leading a healthier and better life today if you make the decision to stop smoking now. Good luck! （請依據上述文章，回答 46~50 題）