—Hi, why are you here?—I ________ for Susan for 15 minutes.A. have been waiting B. have waiting C. am waitingD am been waiting
The winter holiday will begin soon. John _____ to stay with us. A.will be coming B.comes C.is coming
Maria has _____ trouble _____ math, so she often asks her math teacher for help. A.much, understanding B.many, understanding C.not, to understand
Teachers should _____ their students to practice _____ English as much as possible. A.encourage, speaking B.let, speak C.make, speak
—What a nice classroom! —It _____ every day. A.is cleaningB.has cleanedC. is cleaned
We have two ears and one mouth so that we can listen ________we speak.