用疑问代词或者关系代词填空：———— jumped the longest of all in the long jump?填完老顺便说下意思

Who
谁在跳远中跳得最远呀?
*** 猫迷英语专家团提供【Real.American.English.】那这道题呢？ -——— of the following can you often find on a medicine bottle? -_____ I know ,sir.It's instruction.Which This还有几道：1.Most people ______ live in less developed countries are quite poor. 2.The boys ___ is helping the old man is John's brother. 3.People ___ use credit cards to buy things online should be very careful. 4.Do you know the person ___ lost his bike? 5.The necklace ___ she is wearing is beautiful.1. who/that2. who3. who4. who/that5. that