I don't know when Mr.Li ____ back.But I'll call you at once

I don't know when Mr.Li ____ back.But I'll call you at once I don't know when he ____ back tomorrow.Don't worry,I 'll ca 选择填空 ()1.I don’t know when（ ）.When he ( ) ,I’ll call you .A. when _____again?I don't know.but when she_____,I'll let you I don't know when he ____,but when he ____,I will let you kn I don't know （） come back soon. （）back ,I‘ll let you know I went to visit Mr Li.But I don't know his ___.please write Choice 1.I don’t know when he ___,but when he ___,I’ll speak 46.I don't know when he ____a__,but when he ______,I'll let I don't know if she tomorrow.If she tomorrow,I'll call you. I don't know when__back to Beijing.When__,I'll call you. I don't know when she ---,but when she----,i -----you know.