A: If only; Chinese soccer can see
B: Only if; can Chinese soccer see
C: If only; can see Chinese soccer
D: Only if; see Chinese soccer ca
读中国疆域略图,回答以下问题。
A plant makes its own food in its leaves . Water comes to the leaves through the roots . Air gets into the leaves through very small holes . The green coloring in the leaves uses the water and air to make the food for the plant . It also needs sunshine because a plant can make food only when the sun is shining. Animals and people could not live without green plants . They both eat plants . People and some animals also eat the meat of some animals and these animals eat plant
要使一根镍铬合金线接入电路的电阻变大,可采用的方法是( )