为什么Swimming in the sea is (a great fun)in summer.

What's in the lake?Some boys (swimming)in the lake.请问括号里为什么不是“are swimming? at last he s() in swimming across the river it's ______(dance) to go swimming in the river It's Chlidren's Day.The children in Class One are swimming in the swimming pool(h )首字母填空 swimming (at)还是(in) the swimming pool jim with his friends ()in the pool now ,这里为什么填is swimming而不是are swimming swimming已名词化,为什么还能用在I like swimming in the sea中? The fish s in the river happyily.“The fish s ”这里填swim还是swimming? A:Is the boy ( ) in the river?B:No,he( ).He's( )in the swimming pool. Is‘s fun（ ）in the swimming pool选什么A to swim B swimming C swims It's very hot.( )is nice to go( )in the sea.A/That;swimming B,It;swimming,求详解 let's ____(go）swimming in the river what's ____( he) e-mail address --Let's( )in the river!--No,it's dangerous.是swim还是swimming In summer,children swim in the swimming pool and it's very_____【relax】 In the second photo.I am swimming at the pool with my friends.为什么要用am swimming? The ducks are swimming in the river.为什么用介词in,而不用on They are in front of the slide It' s opposite the swimming pool 为什么Swimming in the sea is (a great fun)in summer.